ANKARA- The sacking of U.S. Secretary of State Rex Tillerson may delay a deal between Ankara and Washington to pull Kurdish fighters out of the Syrian town of Manbij, but Turkey still expects U.S. help, President Tayyip Erdogan's spokesman said on Thursday.

Turkey has waged a military operation for nearly two months inside Syria along its frontier against the U.S.-backed Kurdish YPG militia, which Ankara considers terrorists.

So far, the Turkish operation has taken place in Syria's Afrin region, an area where Washington has no troops on the ground.

But Turkey has repeatedly said it also plans to drive the Kurdish group from Manbij, 100 km (60 miles) further east, where U.S. special forces have been based providing support to the YPG to fight against Islamic State militants.

The issue has caused a crisis in relations between the United States and its main Muslim ally within NATO, even raising the prospect of direct confrontation on the ground if the Turks should advance on Manbij without agreement from Washington to pull its troops out of the way.

Tillerson had taken the leading role in recent weeks in U.S. diplomatic efforts to resolve it, visiting Turkey last month and promising to find a solution for Manbij.

But the fate of that initiative appeared unclear after President Donald Trump abruptly removed Tillerson from office on Monday and named CIA chief Mike Pompeo to succeed him.

Turkish Foreign Minister Mevlut Cavusoglu had been due to travel to Washington next week, and Ankara had repeatedly said it expected him to finalise an agreement for the YPG to leave Manbij and U.S. and Turkish troops to secure the area jointly. Washington has not confirmed the details of any such agreement.

Following Tillerson's sacking, Turkey announced that Cavusoglu's trip would be postponed.

President Tayyip Erdogan's spokesman Ibrahim Kalin acknowledged on Thursday that Tillerson's firing was likely to cause a delay in the Manbij plan, but said Ankara still expects Washington to keep its "promises".

"Tillerson is not in a position to carry out meetings now and Pompeo is not informed on the issues, so it will cost us 1-2 weeks, but we will continue working on this," Kalin told state broadcaster TRT in an interview.

"As part of the talks held with the United States, we want to see the YPG removed from Manbij as a first step," he said.

Relations between the United States and Turkey have been deeply strained in recent months, over Syria policy and also over Turkish accusations that Washington has sheltered a cleric Ankara blames for plotting a failed coup, and a U.S. court case that included testimony of top level corruption in Turkey.

Kalin said an agreement between the United States and Turkey over Manbij was binding, and that a change in the U.S. Secretary of State would not impact it.

He also said Turkey expected Turkish forces and their rebel allies to clear Afrin of fighters "very soon".

(Reporting by Tuvan Gumrukcu and Ece Toksabay Editing by David Dolan and Peter Graff) ((tuvan.gumrukcu@tr.com; +903122927021; Reuters Messaging: tuvan.gumrukcu.thomsonreuters.com@reuters.net))