Under a 2019 agreement, Russia and Turkey agreed that Russian military police and Syrian border guards would command a Syrian-Kurdish militia 30 kilometers (19 miles) away from the Turkish border.
Ankara considers the militia to be a terrorist organization.
Erdogan told Putin in a phone call that “a terror-free zone with a depth of 30 kilometers from the Turkish border… has not been established, and that it is imperative to secure these areas,” the Turkish presidency said.
He pointed to the “ongoing attacks” by the Kurdish militants on Turkey.
Erdogan said last week that Turkey will soon launch another military operation in northern Syria to create a “safe zone” along the border.
The United States has warned against launching another operation because the uneasy NATO ally would endanger US forces.
Turkey has launched three offensives in Syria since 2016 to crush Syrian Kurdish fighters who have assisted the US-led campaign against the extremist group Islamic State.
Ankara claims these fighters have ties to the Kurdistan Workers’ Party (PKK), which has been waging an insurgency against the Turkish state since 1984 and is listed as a terrorist group by the European Union and the United States.