The US-led, 79-nation coalition against ISIS has now begun "our deliberate withdrawal from Syria," The Times cited Col. Sean Ryan, the spokesman for the alliance, as saying.
He did not provide any more information about "specific timelines, locations or troop movements," The Times said. INSIDER has contacted the Department of Defense and the State Department for comment.
The news comes after weeks of chaotic mixed messages, which began when President Donald Trump announced his plan to pull the 2,000 US troops out of Syria on December 19.
He said, inaccurately, that it was because ISIS had been "defeated."
The president said he wanted the troops out in 30 days, but later rowed back his comments . His administration later lengthened the timeline for withdrawal.
The US was hoping that Turkey would remain in Syria to fight the remnants of ISIS, which is not totally defeated, either in Syria or elsewhere.
Washington wanted assurances that Turkey would not attack Kurdish militants alongside whom the US had been fighting, but whom Turkey considers terrorists after the US leaves.
Secretary of State Mike Pompeo said on Thursday that the US would carry out with its withdrawal plans despite Erdogan and Bolton's disagreement, Reuters reported.
The decision to withdraw from Syria has been controversial even within the US government.
Jim Mattis , the former US defense secretary, and Brett McGurk , the top US official leading the coalition against ISIS, both resigned over it.