ISTANBUL (AP) — Turkey’s president slammed a U.S.-backed Syrian Kurdish militant group Sunday and said he’ll clear his country’s border with Syria of “terrorists.”

President Recep Tayyip Erdogan told a rally in the central province of Karaman his country would not allow “terror nests” near its border, referring to areas held by the People’s Protection Units or YPG in northern Syria.

Turkey considers the YPG an extension of a Kurdish insurgency within its own borders, and launched an operation in August 2016 to clear part of its border of their and the Islamic State group’s presence.

Erdogan announced an expanded list of areas to be cleared. “We will clean Afrin of terrorists, we will clean Manbij of terrorists. We will clean Tel Abyad, Ras al-Ayn and Qamishli of terrorists,” he said.

Turkey has a military presence in the western Syrian province of Idlib as part of a de-escalation agreement struck with Russia and Iran. The province borders YPG-controlled Afrin and Turkey has threatened to attack the group there.