Syrian Kurdish leaders said a deal with Damascus, brokered by Russia, centers for now on army troops deploying along the border and the two sides will talk politics later.
Top Kurdish politician Aldar Xelil said "the emergency measure" with oversight from the government's key ally Russia was meant to block Turkish attacks at the border.
Washington said on Sunday it will withdraw its 1,000 troops from Syria in the face of an expanding Turkish offensive, while Damascus struck a deal with Kurdish forces to redeploy at the border - victories for Syrian President Bashar al-Assad.
The remarkable turn of events kicked off a week ago when US President Donald Trump decided to withdraw forces from two outposts in northern Syria, where American troops have been stationed for years.
The move opened the way for Turkey's incursion into northeast Syria within days, targeting the Kurdish YPG milita and its allies who control the region.
Syrian army soldiers are now poised to enter border territory from the town of Manbij to Derik, under the deal with the Syrian Democratic Forces (SDF), which the YPG spearheads and which controls the northeast.
"After the Americans abandoned the region, and gave the green light for the Turkish attack, we were forced to explore another option, which is talks with Damascus and Moscow to find a way out and thwart these Turkish attacks," senior Kurdish official Badran Jia Kurd said.
"This is a preliminary military agreement. The political aspects were not discussed, and these will be discussed at later stages."
State media said army units entered the town of Tel Tamer in northeast Syria on Monday, some 35 km from a focal point of the Turkish offensive.
"The priority now is protecting the border's security from the Turkish danger," Xelil said. "We are in contact with the Damascus government to reach common (ground) in the future."