U.S. President Donald Trump said Thursday that Washington may pull out of its involvement in Syria "very soon," in comments that seem to have caught the U.S. State Department off guard.

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Speaking at a rally, Trump said that "we're knocking the hell out of ISIS. We'll be coming out of Syria, like, very soon. Let the other people take care of it now.

"Very soon, very soon, we're coming out. 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, quickly," he said.

The United States has around 2,000 military personnel in Syria, deployed as part of the U.S.-led coalition’s campaign against Islamic State.

Contradicting Trump, the U.S. State Department said it was unaware of any plans to withdraw U.S. troops from Syria.

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Assad, who is supported by Russia and by Shi’ite militias backed by Iran, has said he wants to take back every inch of Syria.

The U.S.-led coalition was set up in 2014 to battle Islamic State fighters in both Syria and Iraq, who were largely defeated last year. Some 2,000 U.S. forces remain on the ground in Syria, allied to the Kurdish-led SDF alliance, which holds the largest swathe of territory still outside the control of the government.

The Syrian civil war, now entering its eighth year, has killed hundreds of thousands of people and driven more than 11 million from their homes, while drawing in regional countries and global powers supporting client factions on the ground.

U.S. forces in Syria have already faced direct threats from Syrian and Iranian-backed forces, leading to the shoot-down of Iranian drones and a Syrian jet last year, as well as to tensions with Russia. But this may have been the largest single assault on a U.S.-accompanied position to date.

Still, these episodes have been sporadic. U.S.-backed SDF and the pro-Syrian forces had largely avoided direct confrontation while both were fighting the common Islamic State enemy. Moscow and Washington maintain contacts in eastern Syria to prevent unexpected confrontation between forces they support.