WASHINGTON - US Secretary of State Mike Pompeo Monday held a phone conversation with his Turkish counterpart over the situation in Syria, the State Department said in a statement.

Pompeo and Turkish Foreign Minister Mevlut Cavusoglu "discussed ongoing US-Turkish engagement as part of the deliberate and coordinated withdrawal of US forces from Syria," according to the statement.

Pompeo reiterated the US commitment to addressing Turkish security concerns along the Turkey-Syria border, while emphasizing the protection of forces that worked with the United States in defeating the Islamic State (IS), referring to the Kurdish militia.

The United States and Turkey have been quarreling over the Kurdish militia in northern Syria, a US ally in the anti-IS campaign but seen as a terrorist group by Ankara.

Washington has proposed to set up a 32-km safe zone in northeastern Syria, a move welcomed by Ankara.

Turkish President Recep Tayyip Erdogan made clear on Monday that the safe zone must not be another new ground against Turkey, adding that its aim should be keeping terrorist organizations away from Turkey's border.

Brett McGurk, former US envoy for the global coalition to defeat the IS, criticized the safe zone proposal "with no process or analysis" in his piece on the Washington Post last Friday, arguing thousands of Kurds might be displaced under the plan.

Cavusoglu, who will travel to Washington on Feb 6 for discussion on Syria, said last week that whether the Turkish and American understanding of the safe zone are in agreement or in conflict would become clear following talks between the two sides.

The situation in Syria has been volatile in the past weeks following Washington's decision to withdraw troops from the war-torn country and the deaths of four Americans in a bomb attack which the IS claimed responsibility for.