Ras al Ain is one of two towns on the Turkish-Syrian border that have been the main targets of Turkey's offensive to push back Kurdish fighters and create a "safe zone" inside Syria that is more than 30km deep.

Turkey paused the offensive on Thursday night for five days under a deal agreed between President Tayyip Erdogan and US Vice President Mike Pence.

Erdogan has warned that Turkey will resume the assault when the deadline expires on Tuesday if the SDF has not pulled back from the safe zone area.

"We don't have any more fighters in the city," SDF spokesman Kino Gabriel said, referring to Ras al Ain.

His comments came after Ankara said dozens of vehicles had entered and left Ras al Ain, which is largely surrounded by Turkish forces and their Syrian rebel allies, over the weekend.

Rebel spokesman Major Youssef Hamoud told Reuters that the SDF had "not yet completely" pulled out of Ras al Ain.

Turkey launched its offensive after President Donald Trump announced he was withdrawing US troops from northeastern Syria. His move was criticised in Washington and elsewhere as a betrayal of Kurdish allies who had fought for years alongside US troops against Islamic State.

However, Trump is now leaning in favour of a new military plan to keep about 200 US troops in eastern Syria near the Iraq border, the New York Times said on Sunday.

Ankara is seeking to set up the zone as a buffer as it regards the YPG, the main component of the SDF, as a terrorist group because of its links to Kurdish insurgents in southeast Turkey. The YPG has been a close US ally in the fight against Islamic State.

The US pull-out has also created a vacuum that Russia, Syrian President Bashar al-Assad's most powerful backer, has looked to fill. Syrian and Russian forces, invited by Kurdish authorities, last week entered the two border cities of Manbij and Kobani vacated by US troops.

At a meeting on Tuesday in the Russian city of Sochi, Erdogan and Russian President Vladimir Putin will discuss the issue of YPG withdrawal from Manbij and Kobani, Turkish Foreign Minister Mevlut Cavusoglu said.

"We believe we can reach an agreement with them to work together in the future, just like we have before," Cavusoglu said on Sunday.

Moscow has called the Turkish offensive into Syria "unacceptable" and said it should be limited.

Although the truce held for the first two days, Turkey's defence ministry said on Sunday one of its soldiers was killed and another wounded after a YPG attack with anti-tank and light arms hit a reconnaissance and surveillance mission in Tel Abyad, the other town seized by Turkey in its offensive.

It said Turkish forces had responded to the attack and said the YPG had committed 22 violations of the deal since it begun.

On Friday the Kurdish militia accused Turkey of violating the pause by shelling civilian areas in the northeast. A senior Turkish official denied the accusations.

Trump's sudden troop withdrawal from Syria and the Turkish attack on the SDF have alarmed Western countries, which fear it could allow thousands of Islamic State fighters detained by the Kurdish-led force to escape and regroup.

Australian Associated Press