By Daren Butler and Raya Jalabi

ISTANBUL/BAGHDAD (Reuters) – Turkey said on Saturday it would take security and other steps in response to a planned independence referendum in northern Iraq’s Kurdish region that it called a “terrible mistake”, as a Kurdish delegation was in Baghdad for talks on the crisis.

The Turkish parliament was to convene later on Saturday to vote on extending a mandate that authorizes Turkish troop deployments to Iraq and Syria and Prime Minister Binali Yildirim alluded to possible military moves on Saturday.

The United States and other Western powers have also urged authorities in the semi-autonomous Iraqi region to cancel the vote planned for Monday. They say the move by the oil-producing Kurdish area distracts from the fight against Islamic State.

In Iraq, a Kurdistan regional government delegation arrived in Baghdad on Saturday for talks with Iraqi government in a bid to defuse tensions, but a senior Kurdish official said the vote was going ahead.

“The delegation will discuss the referendum but the referendum is still happening,” Hoshiyar Zebari, a top adviser to Kurdish leader Massoud Barzani, told Reuters.

Asked if a cross-border operation was among the options, the Turkish premier told reporters: “Naturally, it is a question of timing as to when security, economic and security options are implemented. Developing conditions will determine that.”

Ankara, which has NATO’s second-largest army, warned on Friday the Iraqi vote would threaten security and force it to slap sanctions on a neighbor and trading partner, although it did not specify what measures it might take. [L5N1M321K]

Turkey, home to the largest Kurdish population in the region and fighting a Kurdish insurgency on its soil, has warned that any break-up of neighboring Iraq or Syria could lead to a global conflict. The Kurdish region exports oil through Turkey.

“TERRIBLE MISTAKE”

The spokesman of Turkish President Tayyip Erdogan kept up the diplomatic pressure on Saturday.

“If the referendum is not canceled there will be serious consequences. Erbil must immediately refrain from this terrible mistake which will trigger new crises in the region,” spokesman Ibrahim Kalin wrote on Twitter.

Militants from the Kurdistan Workers Party (PKK) launched a rocket and mortar attack from the Iraqi side of the border on Turkey’s Semdinli district on Saturday, killing one Turkish soldier and a worker in the area of a military base, the Hakkari governor’s office said in a statement.

The PKK launched its separatist insurgency in 1984. More than 40,000 people have been killed in the conflict. It is designated a terrorist group by Turkey, the United States and European Union.

The Turkish president, who chaired back-to-back meetings of Turkey’s cabinet and National Security Council on Friday to discuss the situation, was expected to attend Saturday’s parliamentary session on extending the Turkish troop deployment in the region. Parliament is expect to pass the measure.

The Iraqi army’s chief of staff, Lieutenant General Othman al-Ghanmi arrived in Turkey on Saturday for talks with his Turkish counterpart, General Hulusi Akar, state-run Anadolu agency reported.

It said they would discuss the referendum, measures to protect Iraq’s territorial integrity and a joint anti-terror fight.

The Turkish army launched a highly visible military drill on Monday near the Habur border crossing to Iraq. Military sources said the drill was due to last until Sept. 26, a day after the planned vote.

The second stage of that operation was continuing with the participation of additional units, the Turkish armed forces said in a written statement on Saturday.

Turkey has for years been northern Iraq’s main link to the outside world. It has built strong trade ties with the semi-autonomous region, which exports hundreds of thousands of barrels of oil per day through Turkey to international markets.

(Additional reporting by Maher Chmaytelli in Baghdad; Writing by Daren Butler; Editing by Mark Heinrich and Edmund Blair)