Turkey's Foreign Minister Mevlut Cavusoglu said on Tuesday that Washington is stalling the implementation of an agreement to create a "safe zone" in northeast Syria.
The NATO allies carried out their first joint military land patrol in the region on Sunday. Turkey wants the operations to expand rapidly and push back Kurdish forces 20 miles (32 km) from the border, creating a zone which Ankara says should be controlled by Turkish troops.
Cavusoglu said Turkey wanted to work with the United States, but was prepared to clear the area of Kurdish YPG fighters itself if necessary.
"Yes, there are some joint patrols but other than that, the steps that have been taken or the steps that are said to be taken are cosmetic steps," he told reporters in Ankara.
"We are seeing that the United States is entering a stalling process... and that it is trying get Turkey accustomed to this stalling process."
Cavusoglu said Washington's approach so far had served the Syrian Kurdish YPG forces more than Turkey. The YPG, which has been a main US ally in the fight against Islamic State in Syria, is considered a terrorist organization by Ankara, which says it is an extension of Kurdish militants in Turkey.
President Tayyip Erdogan said last week Turkey also aims to send 1 million of the 3.6 million Syrian refugees it hosts to the planned safe zone in northern Syria.