Turkish and Russian patrols began in Syria's northwestern Idlib region on Friday as part of a deal agreed in Sochi last September.
The agreement between Russia and Turkey included setting up a demilitarized zone, ranging between 15-20 kilometers, around the region.
That zone separates regime forces from Hayat Tahrir al-Sham (HTS), which holds Idlib.
"Today Russian patrols will start outside of Idlib in the border region (and) Turkish armed forces' patrols will begin in the demilitarized zone," Turkish Defense Minister Hulusi Akar said Friday.
The patrols are an important step in preserving stability and reaching a ceasefire, he added.
Meanwhile, US-backed fighters said they will resume their assault on ISIS' last, small patch of ground in eastern Syria if no more civilians come out by Saturday afternoon.
The Syrian Democratic Forces (SDF) have slowed their offensive on the militant enclave at Baghouz near the Iraqi border to allow many thousands of people to leave over the past few weeks.
The head of the SDF media center, Mustafa Bali, said no more people had emerged on Friday.
"We are waiting for tomorrow morning or perhaps until the afternoon, we'll give another space, for the possibility that civilians are present and the chance to get them out," he said.
After that, "if no civilian or terrorist comes out, we will launch our military operation anew."
The capture of Baghouz will mark the end of ISIS’ territorial rule over populated areas of Iraq and Syria, and the culmination of the US-backed military campaign waged by the SDF for four years.
