President Trump greets US troops in Iraq

US President Donald Trump and First Lady Melania Trump have made a Christmas visit to US troops in Iraq, the White House has confirmed.

They travelled there unannounced "late on Christmas night" to thank troops for "their service, their success and their sacrifice", it said.

Trump said the US had no plans to pull out of Iraq, Reuters reports.

It comes days after Defence Secretary Jim Mattis quit over disagreements about strategy in the region.

The US still has some 5,000 troops in Iraq to support the government in its fight against what remains of the Islamic State (IS) group.

Trump and his wife made a visit to al-Asad airbase to meet military personnel in the base's restaurant.

Trump said the US could use Iraq as a forward base if "we wanted to do something in Syria", Reuters news agency reports.

He defended his decision to withdraw US troops from Syria during the visit, saying: "A lot of people are going to come around to my way of thinking."

He announced the decision to pull US troops out of Syria last week.

During the visit he got a standing ovation from troops as he entered a dining hall and walked around greeting them, posing for selfies and signing autographs.

He said the reason for the visit was to personally thank them for helping to defeat IS, adding: "Two years ago when I became president they were a very dominant group, today they're not so dominant any more. Great job."

However, a planned meeting between Trump and Iraqi Prime Minister Adel Abdul Mahdi was cancelled. Mahdi's office said it was because of disagreements on how to conduct the meeting. A phone call between the two leaders was held instead, officials added.

Trump's visit lasted about three hours. On his way home he stopped at Ramstein Air Base, Germany, where he was to meet more US troops.