Turkey is not softening its stance on the U.S.-backed Kurds in northern Syria, whom it has threatened to attack much to the alarm of American officials. Speaking to CNBC in Doha Sunday, Turkish Foreign Minister Mevlut Cavusoglu maintained that Ankara would not accept continued Kurdish paramilitary presence in the area. He argued that contrary to Pentagon warnings, Turkish actions would not endanger U.S. troops working alongside the Kurdish People's Protection Units (YPG) that his government views as a primary enemy. "We are not risking American soldiers' lives, our target is the PKK (Kurdistan Workers' Party) and YPG terrorist organization, as it was in Afrin," Cavusolgu said, referring to Turkey's January offensive against Kurdish paramilitary units in the Kurdish enclave of northern Syria. Erdogan's focus on the Kurds as a primary threat has complicated Washington's plans in Syria, which include relying on YPG fighters to push out the Islamic State. Turkish President Recep Erdogan threatened on Friday that his forces would enter the northern Syrian town of Manbij if the U.S. doesn't remove the Kurdish fighters. "But if America believes that they are the shelter, the protector of this terrorist organization, that is something else," the minister said. "And we have the channels between the militaries to avert any friendly fire or accident, we have this channel and we have good mil-to-mil (military-to-military) cooperation as well."

Pentagon: Unilateral military action is 'of grave concern'

The White House has repeatedly warned against carrying out any such plan, and the threat from Erdogan prompted a call with President Donald Trump the same day during which the two agreed to "more effective coordination" between their countries' operations in Syria. At least 2,000 U.S. troops are working alongside the Kurdish Syrian Democratic Forces (SDF) in the country's north. The Pentagon said that "unilateral military action into northeast Syria by any party, particularly as U.S. personnel may be present or in the vicinity, is of grave concern." While Ankara and Washington are allies against IS in Syria, the two are at loggerheads over U.S. support for the YPG — the backbone of the Kurdish Syrian Democratic Forces — which the Pentagon says has been vital in the anti-IS fight and in ridding much of northern Iraq and Syria of the terrorist group's presence. Turkey stresses the group's ties to the separatist PKK, a Turkish and U.S.-designated terrorist group that's carried out a violent decades-long insurgency in Turkey.

Turkish army troops gather near the Syrian border at Hassa, in Hatay province on January 21, 2018. Bulent Kilic | AFP | Getty Images