DOHA - Turkish President Recep Tayyip Erdogan and his US counterpart, Donald Trump, discussed over phone Ankara’s future military operation in the east of Syria, Erdogan’s aide Ibrahim Kalin told reporters Saturday on the sidelines of the Doha Forum.

On Friday, Erdogan said that Ankara was ready to launch an operation in the Syrian Manbij against the Kurdish People’s Protection Units (YPG) if the United States does not withdraw them from the area. Erdogan discussed the situation in Syria with Trump on the same day.

“Yes, of course,” Kalin said, asked whether the two leaders had discussed possible operation in Manbij.

Erdogan shared with Trump his concerns over growing military presence of the YPG, which is supported by the United States, and he agreed with the president to coordinate military actions on the Turkish-Syrian border, Kalin added.

“So, our military has now been instructed to coordinate their efforts on the ground so that we don’t have this terrorist activity along the Turkish-Syrian border,” Kalin said.

Turkey and the United States have had tense relations in recent years, in part due to Ankara’s concerns over US support for the YPG, viewed by the Turkish authorities as an affiliate of the Kurdistan Workers’ Party (PKK), listed as a terrorist organization in Turkey, the United States and the European Union. Ankara has also repeatedly accused Washington of failing to fulfill its promises regarding the withdrawal of the YPG from Syria’s Manbij.

Turkey has been claiming that the YPG presence near its border hampers its national security. Earlier this year, Ankara conducted an offensive against the Kurdish militia in Syria’s northern border city of Afrin. Turkey is also currently engaged in an operation to eliminate Kurdish strongholds in northern Iraq.