Earlier, the White House said President Donald Trump and Turkish President Recep Tayyip Erdogan talked by telephone about a possible creation of a safe zone in northern Syria.
In addition, top US Defense Department officials will welcome their Turkish counterparts this week for talks on the conflict in Syria, according to the White House.
Trump announced in December that the United States would leave Syria. However, no exact timeline for the return of the 2,000 troops was announced.US troops have been operating in Syria as part of an international coalition for about five years without the permission of the Syrian authorities or the UN Security Council. The United States has in particular supported the Kurdish militia that controls the eastern Euphrates territories and opposes the Syrian government.