ANKARA, June 12 (Xinhua) -- The language used in Pentagon's letter which threatened to remove Turkey from the F-35 fighter jet program was "not in the spirit of the alliance," Turkish Defence Minister Hulusi Akar said on Wednesday.
Last week, U.S. acting Secretary of Defence Patrick Shanahan informed Akar in a letter that the F-35 fighter jet training program for Turkish pilots would halt over Ankara's purchase of the S-400s, and all Turkish trainees would have to leave his country by July 31.
Akar said in a statement released by Turkish Defence Ministry website that Turkey is preparing a response to the Pentagon's letter.
He added that he was set to discuss the issue with Shanahan by phone on Thursday, and that both ministers will meet in Brussels during a NATO defense ministerial meeting at the end of June.
"All topics are on the table and we are continuing to openly and clearly express our known views. We will continue to maintain the same attitude and stance," Akar was quoted as saying.
The United States repeatedly warned it will cut off Ankara's purchase of F-35 fighter jets if the Turkish government goes ahead with plans to buy Russian S-400 air defense system, triggering a heated dispute between the two NATO allies.
Washington has already suspended deliveries of parts and services related to Turkey's receipt of the multi-million dollar jets.