- We are taking another step towards establishing a 30-kilometer security zone along our southern border, the president says.
According to Erdogan, the plan is to "clean up" the cities of Tal Rifaat and Manbij in northern Syria, and then "step by step" advance into other regions.
The statement comes after Erdogan repeatedly threatened recently with an offensive against the terrorist Kurdish guerrilla organization PKK.
An effort will also be directed at the YPG, which Turkey equates with the PKK.
"We will see who supports Turkey's legitimate security efforts and who opposes them," Erdogan said.
The Kurdish-led Syrian Democratic Forces (SDF) say they have been expecting an attack for some time.
"An attack puts the war against IS on hold"
SDF warns that such a Turkish military operation risks undermining the fight against the terrorist movement IS in northeastern Syria.
"In the event of an attack, we will put an end to the war against the Islamic State, in order to launch military action against the Turkish invasion," Farhad Shami, a spokesman for the SDF, told AFP.
The United States last week warned of a military operation in the region.
President Erdogan said as recently as this weekend that an offensive in northern Syria could be staged even without US approval.
Russia and Turkey concluded an agreement in 2019 that the countries' military would control an area near the border and 30 km into Syria.
- Its creation is absolutely necessary, says Erdogan.