Turkey’s President Recep Tayyip Erdogan says Ankara will launch a military operation in a Kurdish-controlled area of in Northern Syria.
Erdogan said both Russia and the United States have been told of the planned operation but did not say when it would begin.
It would be the third Turkish incursion into Syria in as many years.
"We will continue our struggle against those who` are targeting our country as enemies and terrorist groups such as FETO, Daesh, and the PKK," Erdogan said.
Erdogan has warned of launching an offensive east of the Euphrates before but put plans on hold after the US promised to create a buffer zone clear of Kurdish YPG fighters along Syria's border instead.
But Ankara has accused Washington of stalling the process and Sunday's announcement suggests Erdogan has lost patience with his American allies.
The group was Washington's main ally on the ground in Syria during the battle against the so-called Islamic State, but Turkey sees it as a terrorist organisation.
The US says discussions with Turkey on establishing a safe zone are continuing.