Top advisers for Turkey's President Tayyip Erdogan and U.S. President Joe Biden spoke on the phone on Tuesday, marking the first official contact between the two countries since Biden took office.
Erdogan's Chief Foreign Policy Adviser Ibrahim Kalin and U.S. National Security Adviser Jake Sullivan discussed issues regarding Syria, Libya, the eastern Mediterranean, Cyprus, and Nagorno-Karabakh, Turkey's official news agency Anadolu reported.
Kalin told Sullivan that joint efforts were needed to find a solution to present disagreements between the countries such as Turkey's purchase of Russian S-400 defence systems, and the United States' support for Kurdish militia groups in northern Syria, Anadolu said.
In December, Washington imposed long-anticipated sanctions on Ankara over its acquisition of the Russian-made S-400 defence systems, a move Turkey called a "grave mistake". It also removed Turkey, a NATO ally, from its F-35 fighter jet programme as a result.
Washington says the S-400s pose a threat to its F-35 fighter jets and to NATO's broader defence systems. Turkey rejects this, saying S-400s will not be integrated into NATO, and has offered to form a joint working group to examine the conflicting claims.
Ankara says its purchase of the S-400s was not a choice, but rather a necessity as it was unable to procure missile defences from other NATO allies with satisfactory conditions.