ISTANBUL, Feb. 11 (Xinhua) -- Turkish president's security and foreign policy adviser Ibrahim Kalin has met with U.S. National Security Adviser Herbert Raymond McMaster in Istanbul and discussed in detail issues that are hurting bilateral ties, Turkish media reported on Sunday.

Joint efforts against terrorism, long-term strategic partnership between Turkey and the United States, and the latest developments in the region were among topics under discussion, the Hurriyet daily said.

The meeting came as Turkey has been fighting for Afrin, a district in northwestern Syria being held by U.S.-backed Kurdish militia known as People's Protection Units (YPG), since Jan. 20, and Ankara has threatened to move on to target YPG-held Manbij, while Washington has refused to withdraw its troops from the town as demanded by its NATO ally.

As part of efforts to ease tension in bilateral ties and avoid a direct confrontation in Syria, U.S. Secretary of State Rex Tillerson is expected to visit Ankara in the coming days, while Turkish and U.S. defense ministers are scheduled to meet in Brussels next week.