A U.S. delegation has arrived in Ankara to begin the long-awaited discussions on northern Syria's Manbij, Turkey's Foreign Ministry spokesman said Friday.

Turkey and the U.S. have established a mechanism to address separate issues in working groups, including stabilization of Manbij and prevent any undesirable clashes, following the visit of former U.S. Secretary of State Rex Tillerson to Ankara in February.

Ankara demands that Washington expels the PKK-affiliated People's Protection Units (YPG) from Manbij.

"The second part of this meeting is being held today [Friday]. We are hosting the U.S. delegation," Hami Aksoy told reporters in Ankara during a news conference. The first meeting of the working group on Syria was held on March 8-9 in Washington.

Manbij was captured from the Daesh in 2016 by the U.S.-backed Syrian Democratic Forces (SDF), which is predominantly led by YPG terrorists.

Turkey recognizes the PKK and YPG as organically linked terrorist groups. The U.S., however, while listing the PKK as a terrorist group, has supported the YPG militarily, under the pretext of fighting Daesh.

Aksoy said the details of Friday's meeting will be released after a meeting between Foreign Minister Mevlüt Çavuşoğlu and his U.S. counterpart Mike Pompeo on June 4 in Washington.

Ankara's demands that the U.S. stops arming the YPG and ensures the terrorists withdraw to the east of the Euphrates dates back to former President Barack Obama's time in office.

Though promised, the U.S. is yet to meet Ankara's demands, straining ties between the two countries.

The row over Manbij and Turkey saying that it could launch an operation to clear the YPG terrorists from the region have led to fears of military clashes between the two NATO allies since there are roughly 2,000 U.S. troops in the city.

This January, Turkey launched Operation Olive Branch in northern Syria's Afrin, to clear the terrorist presence in the area.After liberating the city, Ankara said it might take its operations further east to Manbij unless the YPG terrorist group left the strategically important city.

The YPG's ultimate aim is to establish an autonomous region in northern Syria by connecting the northwestern Afrin canton to the Kobani and Jazeera cantons in the northeast, which the Turkish government considers a "terror corridor."

With the continuing operations, Turkey says it will eliminate all YPG threats in northern Syria.