“We emphasized that such a step was very wrong,” Turkey's Deputy Prime Minister and Government Spokesman Bekir Bozdag said, according to Reuters.

“Turkey has reached the limits of its patience. Nobody should expect Turkey to show more patience," he continued.

Turkish President Recep Tayyip Erdogan has also warned against U.S. assistance to Kurds.

The warning comes after the U.S. announced it would aid the Syrian Democratic Forces (SDF), which are led by the Kurdish YPG militia in the area.

The U.S. said it would assist in setting up a 30,000-strong border force.

Secretary of State Rex Tillerson pushed back on Turkey's warning, saying action in the area had been misinterpreted, saying the U.S. is only looking to ”to ensure that local elements are providing security to liberated areas”.

“Some people misspoke. We are not creating a border security force at all,” Tillerson said.

The Pentagon also aimed in a statement to downplay Turkey's concerns, saying they were focused on Syrian fighters and preventing another rise of the Islamic State in the area.

“We are keenly aware of the security concerns of Turkey, our coalition partner and NATO ally. Turkey’s security concerns are legitimate,” the statement said.

Reporter’s code: 50101