By Umar Farooq</p> <p>WASHINGTON (AA) – Friendship was reiterated Tuesday by the Turkish ambassador to the U.S. to describe Ankara’s current relationship with Washington.</p> <p>Serdar Kilic, who has served as ambassador to the U.S. since 2014, called on both nations to "defend, protect, and further strengthen" ties.</p> <p>"We are friends and friendship needs care. We cannot take it lightly. Turkey needs United States. But I can assure you that United States also needs Turkey," Kilic said at a conference on American-Turkish relations in Washington.</p> <p>There are a number issues currently facing the countries' relationship including the U.S.'s support to the YPG/PKK terrorist group in northern Syria and the American response to Turkey's purchase of the Russian S-400 missile defense system.</p> <p>Tensions between the U.S. and Turkey have reached a fever pitch in recent months with Turkey set to begin receiving the Russian system that Washington said will jeopardize Turkey's role in the F-35 fighter jet program and could trigger American congressional sanctions. </p> <p>The U.S. has already suspended deliveries of parts and services related to Turkey's receipt of the multi-million dollar fighter jets.</p> <p>Following protracted efforts to purchase an air defense system from the U.S. with no success, Ankara decided in 2017 to purchase the Russian S-400 system.</p> <p>U.S. officials have advised Turkey to buy the U.S. Patriot missile system rather than the S-400 from Moscow, arguing that the Russian system would be incompatible with NATO systems and expose the F-35 to possible Russian subterfuge.</p> <p>Turkey, however, emphasized that the S-400 would not be integrated into NATO operability and would not pose a threat to the alliance.</p> <p>"Public speeches about imposing sanctions on Turkey, limiting the transfer of F-35s or excluding from the JSF [Joint Strike Fighter] program, in which Turkey is a founding partner and a co-producer, not a customer by the way, is simply counterproductive," said Kilic.</p> <p>"Turkey is ready to proceed with the purchase of Patriot missiles … if we can reach a satisfactory deal in the ongoing negotiations," he added and warned threatening language used by Congress will not help.