Turkey is planning its third offensive in Syria.
The country's President, Tayyip Erdogan, announced they'll carry out a military operation to dislodge Kurdish militia fighters close to its border.
The Kurdish-controlled area is east of the Euphrates in northern Syria.
Turkey had warned they'd carry out military operations there but put them on hold.
That was after agreeing with the U.S. to create a safe zone inside Syria's northeastern border with Turkey that would be cleared of the Kurdish YPG militia.
But Ankara has accused Washington of stalling progress on setting up the safe zone and has demanded it sever its relations with the YPG.
The group was Washington's main ally on the ground in Syria during the battle against Islamic State.
It's further tested U.S.-Turkey relations.
The latter see the YPG as a terrorist organization.
Erdogan said both Russia and the U.S. have been told of the planned operation.
The Kurdish-led administration running north and east Syria has issued a statement objecting to Turkish threats to attack the area, warning any Turkish aggression will open the way for the return of Islamic State.