Trump complained that the US spends trillions of dollars in the Middle East, but get “nothing” in return.

He did not say whether the withdrawal also includes the US halting its air operation against the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) fighters, who remain in Syria.

He told the Ohio workers that the American troops have “knocked the hell out of ISIS”.

“We’re going to have 100 percent of the caliphate, as they call it. Sometimes referred to as land. We’re taking it all back quickly.”

US troops in Syria are mostly stationed in the northern part of the country, and are embedded with the Kurdish YPG, its main ally in fighting ISIL.

Last week, the US State Department denied reports that it reached a deal with Turkey on the presence of American troops in the Kurdish city of Manbij.

Turkey, which recently launched a military operation inside Syria, considers the Kurdish Democratic Union Party (PYD) in Syria and its armed-wing YPG to be “terrorist groups” with ties to the banned Kurdistan Workers’ Party (PKK).

The PKK has waged a decades-long armed fight against the Turkish state that has killed tens of thousands of people.

Ankara seels to expand its operation in Syria’s northwestern Afrin region to other Kurdish-held areas further east, including Manbij, prompting fears for a possible confrontation with US troops.

Last week, Turkey said Ankara and Washington had reached a general agreement on Manbij and that the Turkish side is now waiting for its NATO ally to implement the deal.