U.S., South Korea to defend against ‘evolving’ North Korean threat

South Korean Defence Minister

WASHINGTON/SEOUL (Reuters) – U.S. Defense Secretary James Mattis and his South Korean counterpart agreed during a phone call on Monday to strengthen their defense against “the evolving North Korean threat,” the Pentagon said, amid reports the North may be preparing a new missile test.

Mattis, who is to visit South Korea on Thursday, reaffirmed to South Korean Defense Minister Han Min-koo the U.S. commitment to defend the country and “provide extended deterrence using the full range of U.S. capabilities,” the Pentagon said in a statement.

The South Korean Defense Ministry said in a statement the two sides had agreed to deploy the Terminal High Altitude Area Defense (THAAD) system in South Korea as planned to defend against North Korea’s nuclear and ballistic capabilities.

China has objected to THAAD, saying it will destabilize the regional security balance, leading to calls from some South Korean opposition leaders to delay or cancel it.

Mattis’s visit to the region comes amid reports that the North may be readying to test a new ballistic missile in what could be an early challenge for of U.S. President Donald Trump’s administration.

The North also appears to have restarted operation of a reactor at its main Yongbyon nuclear facility that produces plutonium that can be used for its nuclear weapons program, according to a U.S. think tank.

North Korea has carried out a series of nuclear and missile tests in defiance of U.N sanctions. It conducted its fifth nuclear test in September. North and South are technically still at war because their 1950-53 conflict ended in a truce, not a peace treaty.

Mattis also met Jordan’s King Abdullah at the Pentagon and expressed his deep appreciation for Jordan’s contributions to the fight against Islamic State, the Pentagon statement said.

(Reporting by Idrees Ali and Ju-min Park in Seoul; Editing by Nick Macfie)

South Korean, U.S. Marines tussle in snow in what North brands ‘madcap’ drill

South Korea and US Marines winter drills

By Kim Daewoung

PYEONGCHANG, South Korea (Reuters) – South Korean and U.S. Marines are conducting military exercises on ski slopes in sub-freezing temperatures, including shirtless hand-to-hand combat in the snow, prompting warnings of retaliation from North Korea over “madcap mid-winter” drills.

More than 300 Marines are taking part, simulating combat on the ski slopes of Pyeongchang, host of the 2018 Winter Olympics, amid speculation North Korea could be planning another missile test in defiance of U.N. resolutions.

“U.S. Marine Corps and ROK (Republic of Korea) Marine Corps partnered together at every level to build a camaraderie and friendship of the two countries’ militaries but also to increase our proficiency in the event where we have to fight a war together,” U.S. Captain Marcus Carlstrom told reporters.

The training began on Jan. 15 and ends on Feb. 3 in Pyeongchang, about 180 km (115 miles) east of Seoul.

About 28,500 U.S. troops are stationed in South Korea in joint defense against North Korea, which is under U.N. sanctions over a series of nuclear and missile tests and which regularly threatens to destroy the South and the United States.

Poverty-stricken, reclusive North Korea and the rich, democratic South are technically still at war because their 1950-53 conflict ended in a truce, not a peace treaty.

James Mattis, in his confirmation hearing as U.S. defense secretary, described “the Pacific theater” as a priority and analysts expect new U.S. military spending under President Donald Trump to strengthen the U.S. presence in Asia.

Topping U.S. concerns in the region are North Korea’s nuclear weapons and missile programs and China’s military moves in the South China Sea.

North Korean media was dismissive of the exercises, but warned of retaliation.

“The colonial puppet forces, no more than a rabble, are keen on escalating the tension and the moves to ignite a war at a time when even their American master is at a loss how to cope with the DPRK’s powerful nuclear deterrent,” North Korea’s Minju Joson newspaper, quoted by the KCNA news agency, said.

“… If the south Korean warmongers ignite a war against the DPRK, totally counting on the U.S., the revolutionary forces of the DPRK will wipe out the aggressors to the last man by fully displaying their tremendous might …”

DPRK stands for Democratic People’s Republic of Korea, North Korea’s official name.

Acting South Korean President Hwang Kyo-ahn said on Monday the deployment of a U.S. anti-missile defense system should not be delayed in the face of the growing North Korean nuclear missile threat. [nL4N1FD1A3]

South Korean Defense Minister Han Min-koo said on Friday North Korea’s nuclear weapons and missiles were “a direct and substantive threat” and ordered thorough military readiness, Yonhap News Agency said.

(Additional reporting by Nataly Pak in Seoul; Writing by Hyunyoung Yi and Nick Macfie; Editing by Paul Tait)

North Korean elite turning against leader Kim: defector

North Korea leader Kim Jong Un

By James Pearson

SEOUL (Reuters) – The North Korean elite are outwardly expressing their discontent towards young leader Kim Jong Un and his government as more outside information trickles into the isolated country, North Korea’s former deputy ambassador to London said on Wednesday.

Thae Yong Ho defected to South Korea in August last year and since December 2016 has been speaking to media and appearing on variety television shows to discuss his defection to Seoul and his life as a North Korean envoy.

“When Kim Jong Un first came to power, I was hopeful that he would make reasonable and rational decisions to save North Korea from poverty, but I soon fell into despair watching him purging officials for no proper reasons,” Thae said during his first news conference with foreign media on Wednesday.

“Low-level dissent or criticism of the regime, until recently unthinkable, is becoming more frequent,” said Thae, who spoke in fluent, British-accented English.

“We have to spray gasoline on North Korea, and let the North Korean people set fire to it.”

Thae, 54, has said publicly that dissatisfaction with Kim Jong Un prompted him to flee his post. Two university-age sons living with him and his wife in London also defected with him.

North and South Korea are technically still at war because their 1950-53 conflict ended in a truce, not a peace treaty. The North, which is subject to U.N. sanctions over its nuclear and missile programs, regularly threatens to destroy the South and its main ally, the United States.

Thae is the most senior official to have fled North Korea and entered public life in the South since the 1997 defection of Hwang Jang Yop, the brains behind the North’s governing ideology, “Juche”, which combines Marxism and extreme nationalism.

Today’s North Korean system had “nothing to do with true communism”, Thae said, adding that the elite, like himself, had watched with unease as countries like Cambodia, Vietnam and the former Soviet Union embraced economic and social reforms.

Thae has said that more North Korean diplomats are waiting in Europe to defect to South Korea.

North Korea still outwardly professes to maintain a Soviet-style command economy, but for years a thriving network of informal markets and person-to-person trading has become the main source of food and money for ordinary people.

Fully embracing these reforms would end Kim Jong Un’s rule, Thae said. Asked if Kim Jong Un’s brother, Kim Jong Chol, could run the country instead, Thae remained skeptical.

“Kim Jong Chol has no interest in politics. He is only interested in music,” Thae said.

“He’s only interested in Eric Clapton. If he was a normal man, I’m sure he’d be a very good professional guitarist”.

(Reporting by James Pearson; Editing by Nick Macfie)

U.S. deploys high-tech radar amid heightened North Korea rhetoric: official

radar to spy on North Korea

WASHINGTON (Reuters) – A high-tech sea-based U.S. military radar has left Hawaii to monitor for potential North Korean intercontinental ballistic missile test launches, a U.S. defense official said on Wednesday.

Earlier this month, North Korean leader Kim Jong Un said that the isolated, nuclear-capable country was close to test-launching an intercontinental ballistic missile (ICBM).

The official, speaking on condition of anonymity, said the radar, known as the Sea-based X-band radar (SBX), left on Monday and would reach its destination, about 2,000 miles (3,218 km) northwest of Hawaii, towards the end of January.

The radar is able to track ICBMs and differentiate between hostile missiles and those that are not a threat.

On Tuesday, U.S. Defense Secretary Ash Carter said the U.S. military might monitor a North Korean intercontinental ballistic missile test and gather intelligence rather than destroy it, as long as the launch did not pose a threat.

“If the missile is threatening, it will be intercepted. If it’s not threatening, we won’t necessarily do so,” Carter said,

“Because it may be more to our advantage to, first of all, save our interceptor inventory, and, second, to gather intelligence from the flight, rather than do that (intercept the ICBM) when it’s not threatening.”

Carter’s remarks came just over a week after U.S. President-elect Donald Trump vowed that North Korea would never fulfill its threat to test an ICBM. Trump said in a Jan. 2 tweet: “It won’t happen!”

“The SBX’s current deployment is not based on any credible threat; however, we cannot discuss specifics for this particular mission while it is underway,” Commander Gary Ross, a Pentagon spokesman, said.

(Reporting by Idrees Ali and Phil Stewart; Editing by James Dalgleish)

North Korea says can test-launch ICBM at any time: official news agency

File photo of ballistic missile

SEOUL (Reuters) – North Korea declared on Sunday it could test-launch an intercontinental ballistic missile (ICBM) at any time from any location set by leader Kim Jong Un, saying a hostile U.S. policy was to blame for its arms development.

Kim said on Jan. 1 that his nuclear-capable country was close to test-launching an ICBM.

“The ICBM will be launched anytime and anywhere determined by the supreme headquarters of the DPRK,” an unnamed Foreign Ministry spokesman was quoted as saying by the official KCNA news agency, using the acronym for the country’s name.

The North is formally known as the Democratic People’s Republic of Korea.

U.S. Defence Secretary Ash Carter said on Sunday that North Korea’s nuclear weapons capabilities and ballistic missile defence programs constituted a “serious threat” to the United States and that it was prepared to shoot down a North Korean missile launch or test.

“We only would shoot them down … if it was threatening, that is if it were coming toward our territory or the territory of our friends and allies,” Carter said during an appearance on NBC’s “Meet the Press” program.

The United States said on Jan. 5 that North Korea had demonstrated a “qualitative” improvement in its nuclear and missile capabilities after an unprecedented level of tests last year.

North Korea has been testing rocket engines and heat-shields for an ICBM while developing the technology to guide a missile after re-entry into the atmosphere following a liftoff, experts have said.

While Pyongyang is close to a test, it is likely to take some years to perfect the weapon, according to the experts.

Once fully developed, a North Korean ICBM could threaten the continental United States, which is around 9,000 km (5,500 miles) from the North. ICBMs have a minimum range of about 5,500 km (3,400 miles), but some are designed to travel 10,000 km (6,200 miles) or farther.

On Monday, South Korean defence ministry spokesman Moon Sang-gyun called North Korea’s statement a “provocative announcement” and told a regular news briefing that Pyongyang would face stronger sanctions if it were to launch an ICBM. Unification Ministry spokesman Jeong Joon-hee said there were no signs of any launch preparations.

U.S. President-elect Donald Trump responded to Kim’s comments on an ICBM test by declaring in a tweet last week: “It won’t happen!”

Asked for comment on Sunday, the White House referred to Jan. 3 comments by White House press secretary Josh Earnest in which he said the U.S. military believed it could protect against the threat emanating from North Korea.

In that briefing, Earnest also touted the defensive measures the United States had taken to guard against the threat, such as anti-ballistic missile facilities that had been installed around the Pacific region and diplomatic pressure to discourage North Korea from pursuing its nuclear program.

A U.S. State Department spokesman said last week that the United States did not believe that North Korea was capable of mounting a nuclear warhead on a ballistic missile.

North Korea has been under U.N. sanctions since 2006 over its nuclear and ballistic missile tests. The sanctions were tightened last month after Pyongyang conducted its fifth and largest nuclear test on Sept. 9.

“The U.S. is wholly to blame for pushing the DPRK to have developed ICBM as it has desperately resorted to anachronistic policy hostile toward the DPRK for decades to encroach upon its sovereignty and vital rights,” KCNA quoted the spokesman as saying.

“Anyone who wants to deal with the DPRK would be well advised to secure a new way of thinking after having clear understanding of it,” the spokesman said, according to KCNA.

Here is an interactive guide to North Korea’s nuclear and ballistic missile programmes produced by the Reuters graphics team.(http://tmsnrt.rs/2inl1WO)

(Reporting by Jack Kim and Ju-min Park; Additional reporting by Julia Harte in Washington; Editing by Angus MacSwan and Peter Cooney)

North Korea’s Kim guides special operations drill targeting South

Combat Drills in North Korea

SEOUL (Reuters) – North Korean leader Kim Jong Un guided a special operations drill targeting the South, the North’s media reported on Sunday, as rival South Korea remained on alert for any attempt by the North to take advantage of political turmoil in the South.

The North’s KCNA state news agency report did not say when North Korean forces conducted the combat exercise, nor did it mention the South Korean parliament’s vote on Friday to impeach its president, Park Geun-hye.

Pictures in a Sunday report on the exercise in the North’s Rodong Sinmun newspaper showed what appeared to be a mockup of South Korea’s presidential Blue House as a target.

Park will remain in the Blue House, though her powers have been suspended and assumed by the South’s prime minister while the Constitutional Court weighs parliament’s impeachment vote.

South Korean Prime Minister Hwang Kyo-ahn has urged a high state of military alert in case of any provocation by North Korea, including possible cyber attacks.

“We are ready to retaliate if North Korea makes any provocations and we condemn its malicious threat,” a South Korean military official told Reuters.

Tension on the divided Korean peninsula has been high this year after two North Korean nuclear tests and an unprecedented flurry of ballistic missile tests.

The North’s tests have brought tighter U.N. Security Council sanctions but no indication North Korea and its young leader Kim are willing to compromise on its nuclear and missile programmes.

The Rodong Sinmun pictures included one of Kim observing the exercise through binoculars.

“Watching the brave service personnel independently and pro-actively perform their combat duty destroying specified targets of the enemy, he said with a broad smile on his face: ‘Well done, the enemy troops will have no space to hide themselves, far from taking any counteraction’,” KCNA cited Kim saying.

(Reporting by Ju-min Park and Yun Hwan Chae; Writing by Tony Munroe; Editing by Robert Birsel)

Squeezing North Korea: old friends take steps to isolate regime

Friendship bridge between China and North Korea

By Ju-min Park and Tony Munroe

SEOUL (Reuters) – From kicking out North Korean workers and ending visa-free travel for its citizens, to stripping flags of convenience from its ships, Cold War-era allies from Poland to Mongolia are taking measures to squeeze the isolated country.

More such moves, with prodding from South Korea and the United States, are expected after North Korea recently defied U.N. resolutions to conduct its fifth nuclear test.

North Korea’s limited global links leave most countries with few targets for penalizing the regime on their own.

Mounting sanctions over the years have made Pyongyang more adept at evasion and finding alternative sources for procurement, a recent paper by experts at Harvard University and the Massachusetts Institute of Technology found.

Nonetheless, South Korea has been especially active in pushing the North’s allies for unilateral action in hopes of reining in Pyongyang’s arms program.

“If long-standing friends of North Korea continue to publicly curb their ties with the country, Pyongyang will have fewer places overseas where its illicit networks can operate unhindered or with political cover from the host capital,” said Andrea Berger, deputy director of the proliferation and nuclear policy program at the Royal United Services Institute (RUSI).

South Korean officials have declined to say whether they have made inducements to countries to punish North Korea.

“Presumably in the course of that diplomatic interaction it is also being made clear to Pyongyang’s partners that deeper trade ties with economies like South Korea will not be fully realizable” without taking steps against North Korea, Berger said.

Angola, for one, has suspended all commercial trade with Pyongyang, banning North Korean companies from operating there since the U.N. toughened sanctions in March, a South Korean foreign ministry official told Reuters recently.

Angola was suspected of buying military equipment in 2011 from North Korea’s Green Pine Associated Corp, which is under U.N. sanction, according to a 2016 U.N. report. North Korea had also cooperated with Angola in health care, IT and construction, South Korea’s embassy there said in December.

Angolan officials did not respond to requests for comment, but the country told the U.N. in July it had not imported any light weapons from North Korea in recent years.

North Korea’s export of cheap labor has also been targeted.

Earlier this year, Washington urged countries to curb the use of North Korean workers, who number roughly 50,000 and generate between $1.2 billion and $2.3 billion annually for Pyongyang, according to a 2015 U.N. report.

Poland, which hosted as many as 800 North Korean workers, according to some estimates, this year stopped renewing visas, as did Malta.

Travel restrictions have also increased, with Ukraine recently revoking a Soviet-era deal that allowed visa-free visits for North Koreans.

Singapore, which has been a hub for North Korea-linked trade, will require visitors from the country to apply for visas starting next month, its immigration authority said in July.

DE-FLAGGED

The vast majority of North Korea’s trade is with China, and experts warn sanctions will have limited impact without Beijing’s backing. China condemns Pyongyang’s nuclear program but is also its chief ally and is unwilling to pressure leader Kim Jong Un’s regime too far, fearing a collapse that would destabilize the entire region. That means agreeing significantly tightened U.N. sanctions could be difficult.

Some of the most tangible results of recent efforts to isolate North Korea have seen countries ban its ships from their registries. North Korean-owned vessels are suspected of using other flags to camouflage the movement of illicit cargo.

Landlocked Mongolia, which is among Pyongyang’s steadiest allies but also has close ties with Seoul, canceled the registrations of all 14 North Korean vessels flying its flag, according to a report it submitted to the U.N. in July, even though sanctions compelled it to act on just one of them.

Cambodia, once the most popular flag of convenience for North Korea, ended its registry scheme for all foreign ships in August, although it did not single out North Korea.

The flags of 69 North Korean ships, none of them on a U.N. blacklist, have been de-registered since the U.N. tightened sanctions in March, South Korea’s foreign minister said last month. The North’s merchant fleet is estimated by the U.N. at roughly 240 vessels.

Still, one-off measures by various countries mean Pyongyang can simply shift its business elsewhere – a shortcoming of unilateral actions in general.

China and Russia employ the bulk of North Korean workers and have publicly shown no inclination to halt the practice.

Last week, North Korean state media announced the Sept 19 “inauguration” of its embassy in the Belarusian capital Minsk. However, on Monday, the Belarus foreign ministry said there was no North Korean embassy there, although it did not immediately give further information.

Pyongyang has been known to use diplomatic personnel, several whom have been caught with large amounts of gold or cash, to procure banned equipment or fund illegal activities.

China, experts say, remains the key.

“Rather than being efficient, unilateral actions put psychological pressure on the North,” said Chang Yong-seok, a senior researcher at the Institute for Peace and Unification Studies at Seoul National University. “But like criminal gangs, North Korea won’t cringe much under psychological pressure.”

(Additional reporting by Andrei Makhovsky in Minsk, Herculano Coroado in Luanda and Prak Chan Thul in Phnom Penh; Editing by Lincoln Feast)

North Korea ramps up uranium enrichment, enough for six nuclear bombs a year: experts

Kim Jong Un of North Korea

By Jack Kim and James Pearson

SEOUL (Reuters) – North Korea will have enough material for about 20 nuclear bombs by the end of this year, with ramped-up uranium enrichment facilities and an existing stockpile of plutonium, according to new assessments by weapons experts.

The North has evaded a decade of U.N. sanctions to develop the uranium enrichment process, enabling it to run an effectively self-sufficient nuclear program that is capable of producing around six nuclear bombs a year, they said.

The true nuclear capability of the isolated and secretive state is impossible to verify. But after Pyongyang conducted its fifth and most powerful nuclear test last week and, according to South Korea, was preparing for another, it appears to have no shortage of material to test with.

North Korea has an abundance of uranium reserves and has been working covertly for well over a decade on a project to enrich the material to weapons-grade level, the experts say.

That project, believed to have been expanded significantly, is likely the source of up to 150 kilograms (330 pounds) of highly enriched uranium a year, said Siegfried Hecker, a leading expert on the North’s nuclear program.

That quantity is enough for roughly six nuclear bombs, Hecker, who toured the North’s main Yongbyon nuclear facility in 2010, wrote in a report on the 38 North website of Johns Hopkins University in Washington published on Monday.

Added to an estimated 32- to 54 kilogram plutonium stockpile, the North will have sufficient fissile material for about 20 bombs by the end of 2016, Hecker said.

North Korea said its latest test proved it was capable of mounting a nuclear warhead on a medium-range ballistic missile, but its claims to be able to miniaturize a nuclear device have never been independently verified. [nL3N1BL1ND]

Assessments of the North’s plutonium stockpile are generally consistent and believed to be accurate because experts and governments can estimate plutonium production levels from telltale signs of reactor operation in satellite imagery.

South Korean Defence Minister Han Min-koo this year estimated the North’s plutonium stockpile at about 40 kilograms.

But Hecker, a former director of the U.S. Los Alamos National Laboratory, where nuclear weapons have been designed, has called North Korea’s uranium enrichment program “their new nuclear wildcard,” because Western experts do not know how advanced it is.

PAKISTAN CONNECTION

Jeffrey Lewis of the California-based Middlebury Institute of International Studies said North Korea had an unconstrained source of fissile material, both plutonium from the Yongbyon reactor and highly-enriched uranium from at least one and probably two sites.

“The primary constraint on its program is gone,” Lewis said. Weapons-grade plutonium has to be extracted from spent fuel taken out of reactors and then reprocessed, and therefore would be limited in quantity. A uranium enrichment program greatly boosts production of material for weapons.

The known history of the uranium enrichment project dates to 2003, when the North was confronted by the United States with evidence of a clandestine program to build a facility to enrich uranium with the help of Pakistan.

Former Pakistani President Pervez Musharraf said in his memoirs that A.Q. Khan, the father of that country’s nuclear program, transferred two dozen centrifuges to the North and some technical expertise around 1999.

“It was also clear that the suspected Pakistani connection had taken place, as the centrifuge design resembled Pakistan’s P-2 centrifuge,” Hecker said in a report in May.

Hecker reported being shown around a two-story building in the Yongbyon complex in November 2010 that a North Korean engineer said contained 2,000 centrifuges and a control room Hecker called “astonishingly modern.”

By 2009, the North had likely acquired the technology to be able to expand the uranium project indigenously, Joshua Pollack, editor of the U.S.-based Nonproliferation Review, has said.

North Korea has not explicitly admitted to operating the centrifuges to produce weapons-enriched uranium, instead claiming they were intended to generate fuel for a light water reactor it was going to build.

Despite sanctions, by now North Korea is probably largely self-sufficient in operating its nuclear program, although it may still struggle to produce some material and items, Lewis said.

“While we saw this work in Iran, over time countries can adjust to sanctions,” he said.

(Editing by Raju Gopalakrishnan)

North Korea publicly executes two officials for disobeying Kim Jong Un

File photo of North Korean flag flying on a mast at the Permanent Mission of North Korea in Geneva

SEOUL (Reuters) – North Korea publicly executed two officials in early August for disobeying leader Kim Jong Un, a South Korean newspaper reported on Tuesday, in what would be the latest in a series of high-level purges under the young leader’s rule, if confirmed.

Kim took power in 2011 after the death of his father, Kim Jong Il, and his consolidation of power has included purges and executions of top officials, South Korean officials have said.

Citing an unidentified source familiar with the North, the JoongAng Ilbo daily said former agriculture minister Hwang Min and Ri Yong Jin, a senior official at the education ministry, had been executed.

The report could not be independently verified, and South Korea’s Unification Ministry, which handles North Korea-related matters, did not have immediate comment.

Some previous media reports of executions and purges in the reclusive state later proved inaccurate.

The report of the executions comes soon after the South said North Korea’s deputy ambassador in London had defected and arrived in the South with his family, dealing an embarrassing blow to Kim’s regime.

North Korea rarely announces purges or executions, although state media confirmed execution of Kim’s uncle and the man widely considered the second most powerful man in the country, Jang Song Thaek, in 2012 for factionalism and crimes damaging to the economy.

A former defense minister, Hyun Yong Chol, is also believed to have been executed last year for treason, according to the South’s spy agency.

The JoongAng Ilbo said the two men were executed by anti-aircraft gun at a military academy in Pyongyang.

North Korean state media described Hwang, one of the officials named, as agriculture minister in 2012, and referred to him as a vice minister of agriculture in 2014.

Hwang was killed because his policy proposals were seen as a challenge to Kim Jong Un, JoongAng Ilbo said. Ri was caught nodding off during a meeting with Kim and later investigated for corruption and showing disrespect to the leader, it added.

(Reporting by Ju-min Park; Additional reporting by James Pearson; Editing by Tony Munroe and Clarence Fernandez)

North Korea says missile test simulated attack on South’s airfields

Kim Jong Un watching missile test

By Jack Kim

SEOUL (Reuters) – North Korea said on Wednesday it had conducted a ballistic missile test that simulated preemptive strikes against South Korean ports and airfields used by the U.S. military, a likely reference to the launches of three missiles on Tuesday.

The North’s leader, Kim Jong Un, supervised the exercise that successfully tested the simulated detonation of nuclear warheads mounted on missiles, its official KCNA news agency reported.

It did not give the date of the exercise, as it customarily reports activities of its leader without dates or locations. Rodong Sinmun, the ruling Workers’ Party’s official newspaper, carried photographs of Kim with military aides, apparently observing a ballistic missile exercise.

North Korea fired three ballistic missiles that flew between 500 km and 600 km (300-360 miles) into the sea off its east coast, South Korea’s military said, in defiance of UN Security Council resolutions and the latest in a series of provocative moves by the isolated country after a series of nuclear weapons tests.

“The drill was conducted by limiting the firing range under the simulated conditions of making preemptive strikes at ports and airfields in the operational theater in South Korea where the U.S. imperialists’ nuclear war hardware is to be hurled,” KCNA said.

“And it once again examined the operational features of the detonating devices of nuclear warheads mounted on the ballistic rockets at the designated altitude over the target area.”

Yang Uk, a senior researcher at the Korea Defence and Security Forum and a policy adviser to the South Korean navy, said there was little firm evidence to suggest the North had succeeded in developing a nuclear warhead for missiles.

“But it’s a reminder that they are continuing to pursue nuclear warhead development, and that itself is an escalation of risks for us,” he added.

Tuesday’s missile launches were seen as a show of force a week after South Korea and the United States chose a site in the South to deploy the Terminal High Altitude Area Defence (THAAD) anti-missile system to counter threats from the North.

North Korea had threatened a “physical response” to the move.

“The idea seems to be to signal that (U.S.) war plans cannot succeed because if we activated them, the North Koreans would strike as we made the attempt,” said Joshua Pollack, editor of the U.S.-based Nonproliferation Review.

Late on Tuesday, North Korean state media called U.S. Ambassador to South Korea Mark Lippert a “mentally deranged hooligan” and “a heinous war maniac” for flying in a U.S. fighter jet earlier this month.

Reclusive North Korea occasionally publishes insults of U.S. and South Korean officials.

The North and the rich, democratic South are technically still at war because their 1950-53 conflict ended in an armistice, not a peace treaty. The North regularly threatens to destroy Japan, South Korea and the South’s main ally, the United States.

The U.S. air force said Lippert flew in a familiarization flight in an F-16 on July 12 to gain better understanding of the U.S. and South Korea’s joint defense against North Korea.

(Additional reporting by James Pearson; Editing by Nick Macfie)