Withdrawal of US troops will be 'worst thing' for Iraq: Trump

Pulling out US troops from Iraq will be the "worst thing" for the country, President Donald Trump said on Tuesday, after the Iraqi parliament demanded expulsion of American forces.

Some 5,000 US soldiers are deployed in Iraq as part of the international coalition against the IS terror group. On Sunday, the Iraqi parliament had passed a resolution to terminate the agreement that allows for US troops in the country.

Trump said if Iraq expels US troops now, "I think it's the worst thing that can happen to Iraq".

"If we leave that would mean that Iran would have a much bigger foothold, and the people in Iraq do not want to see Iran running the country," he said.

In a brief interaction with reporters at the Oval Office of the White House, Trump said at some point the US will want to get out of Iraq.

"But this isn't the right point. The other thing is, if we do get out, we've spent a tremendous amount of money on building airports and building one of the largest embassies we have in the world. We want to be reimbursed to the various costs that we have had," he said.

"They're very significant...We don't want to be there forever... I didn't want to be there in the first place to be honest and everybody knows that. That was when I was a civilian I said it, but we were there and they made a decision and I disagreed with that decision very strongly, Trump said.

The president said that but "we're there now we've done a great job. We've gotten rid of the caliphate. 100 per cent of the caliphate is gone, which is ISIS".

The Iraqi parliament's move comes in response to the killing of Maj Gen Qasem Soleimani, the 62-year-old head of Iran's elite al-Quds force and the architect of its regional security apparatus, in a US drone attack in Baghdad on Friday.

The strike also killed Abu Mahdi al-Muhandis, deputy chief of Iraq's powerful Hashed al-Shaabi paramilitary force.