BAGHDAD (Reuters) – Iraq said on Wednesday its U.S.-backed military campaign against Islamic State had retaken around two-thirds of the territory seized by the militants in their lightning sweep across the country’s north and west in 2014.

“Daesh’s presence in Iraqi cities and provinces has declined. After occupying 40 percent of Iraqi territory, now only 14 percent remains,” government spokesman Saad al-Hadithi said in a televised statement, using an Arabic acronym for Islamic State.

That calculation appeared rosier than recent estimates from Washington. U.S. Secretary of State John Kerry told Alhurra TV late last month that Islamic State had lost 44 percent of the territory it had held in Iraq.

Iraq’s military, along with Kurdish peshmerga forces, Shi’ite Muslim militias and Sunni tribal fighters, have recaptured several cities in the past year, including Ramadi, Tikrit and Baiji.

Yet Islamic State still manages to launch deadly attacks in areas under the government’s nominal control. On Wednesday, a suicide car bomb in Baghdad’s Sadr City district killed at least 52 people and wounded more than 78.

Iraqi officials say they will retake the northern city of Mosul this year, but in private many question whether that is possible.

Iraq’s military opened a new front in March against the militants in the Makhmour area, which it called the first phase of a wider campaign to recapture Mosul, around 60 km (40 miles) further north. Progress has been slow, and to date Iraqi forces have taken just five villages.

(Reporting by Stephen Kalin and Ahmed Rasheed; Editing by Dominic Evans)