Turkey cannot handle a new wave of migrants from northern Syria, President Tayyip Erdogan said on Tuesday, adding that Ankara and Washington needed to establish a “safe zone” in the region as soon as possible.

The NATO allies have agreed to establish a safe zone in northeast Syria along Turkey’s southern border, and to clear the area of Syrian Kurdish YPG fighters. On Sunday, Turkish and U.S. troops carried out their first joint military land patrol in the region.