Syria's Kurds have announced a deal with Damascus on a Syrian troop deployment near the border with Turkey, as Ankara continues a deadly cross-border offensive.
The announcement on Sunday came as the United States ordered the withdrawal of almost its entire ground force in Syria.
Defense Secretary Mark Esper said the move to withdraw 1,000 US troops came after Washington learned that Turkey was pressing further into Syria than expected.
Turkey's relentless assault, which has seen air strikes, shelling and a ground incursion manned mainly by Syrian proxy fighters, has killed scores of civilians and fighters since its launch on Wednesday.
The Kurds feel they have been betrayed by the United States, their once formidable ally in the fight against the Islamic State jihadist group, and left to fend for themselves in the battle against Turkish forces.
The massively outgunned Kurds have described their deal with the Syrian government as a necessary step to stop the assault.
Kurdish authorities and foreign powers have warned of a major humanitarian crisis, which has already forced tens of thousands to flee their homes.
They have also warned repeatedly that the hostilities could undermine the fight against Islamic State and allow jihadists to break out of captivity.