The US and Turkey are working together on military plans to clear the Islamic State (IS) group from parts of northern Syria, American officials say.
They said an “Islamic State-free zone” would ensure greater stability along the Syria-Turkish border.
The talks follow a major shift in Turkey’s approach to IS in recent days.
Turkey, which had been reluctant to intervene in Syria, has launched raids against IS and allowed US jets to use a Turkish base.
The Turkish operations have led to tensions with Kurdish militia forces fighting IS in northern Syria.
On Monday Kurdish People’s Protection Units (YPG) said Turkish tanks had shelled their fighters near the key town of Kobane.
Turkey said it was investigating the YPG’s claim.
At the same time, Turkey has admitted launching strikes on the Kurdish PKK group in northern Iraq.
Turkey has battled PKK insurgents on its own territory in a conflict that has killed about 40,000 people since 1984.
Turkey has said it has no plans to send ground troops into Syria.
Efforts by the US and Turkey to set up a buffer zone in northern Syria were revealed by unnamed officials interviewed by US media.
Under the agreement being reportedly finalised, the militants would be removed from a 68-mile (109km) stretch west of the Euphrates River, according to the Washington Post.
Such a deal would significantly increase the scope of the US-led air war against IS in northern Syria, the paper says.
It could also increase tensions with Kurdish fighters, such as the YPG, who control much of northern Syria and are opposed to any Turkish military intervention there, correspondents say.
