By Tom Perry
BEIRUT (Reuters) - Turkey-backed Syrian rebels would like to see a "safe zone" set up in areas of the border they are capturing from Islamic State, but this would need an agreement between the United States, Turkey and Russia, a rebel commander said on Tuesday.
Ahmed Osman of the Sultan Murad insurgent group said he wanted to see a zone established where displaced civilians could live free from the risk of Syrian government air strikes.
Osman also told Reuters that the Turkey-backed rebels would soon be forced to confront Kurdish militias because they had not withdrawn from the area as demanded by the United States and Turkey.
The Turkish military launched an incursion into northern Syria last month with the stated aims of clearing Islamic State from its last foothold at the border and preventing expansion by the Kurdish YPG militia that is seen as a threat by Ankara.
Turkey, a major sponsor of the insurgency against President Bashar al-Assad, has long argued for the establishment of a safe zone in Syria where there would be no fighting, saying this would help stem migrant flows from the country.
Osman said his rebel group would like such a zone set up in 90 km (55 mile) stretch of the border between the towns of Jarablus and Azaz.
"Our goal is to secure the northern and eastern (Aleppo) countryside from Daesh and the Kurdish separatists. But if a safe zone happened for the security of our people at the Turkish-Syrian border, this is something excellent that would please us," he said.
"Turkey on its own cannot do that. There must be unity of opinions among Turkey, Russia and America ... if they agree on this matter then there will be a secure zone."
Backed by Turkish troops, Sultan Murad and other rebel groups fighting under the banner of the Free Syrian Army captured Islamic State's last remaining territory on the Syrian-Turkish border on Sunday.
They have also clashed with Kurdish-allied forces that Turkey wants to prevent from further expansion in northern Syria. The Kurdish YPG militia has already captured swathes of territory from Islamic State with support from the U.S.-led coalition against the group.
An alliance of militias backed by the YPG and known as the Syrian Democratic Forces last month drove Islamic State from the city of Manbij, which is located to the west of the river Euphrates and is also a target of the Turkey-backed operation.
Since the Turkey-backed operation got underway, the rebels have clashed with the Kurdish-allied militia north of Manbij. The Turkey-backed rebels say they want to capture the city from the Kurdish-allied forces.
Fighting between the sides was halted last week after the United States called on Turkey to stay focused on the fight against Islamic State and not to target Kurdish forces.
Osman said the rebels had temporarily halted fighting on that front to focus on IS-held territory and to give the YPG a chance to withdraw to the east bank of the Euphrates.
"But this did not happen unfortunately. Therefore we are obliged to confront them militarily," he said. Asked when, he said: "Soon".
The YPG says it has withdrawn from the Manbij area.
(Reporting by Tom Perry; Editing by Dominic Evans and Hugh Lawson)