Turkish Foreign Minister Mevlüt Cavusoglu criticized on Thursday a letter to the Acting Minister. US Secretary of Defense Patrick Shanahan regarding Turkey's removal from the F-35 fighter jet program, Hurriyet Daily reported. 

According to him, the language used in a letter sent from Washington to Ankara regarding Turkey's removal from the F-35 fighter jet program does not suit the spirit of alliance.

“Shanahan said on June 11 he will discuss Washington's spat with Ankara over its purchase of Russia's S-400 missile defense system with his Turkish counterpart Hulusi Akar on June 12,” the source noted.

According to Foreign Policy magazine, Shanahan in a letter sent to Turkish Minister of National Defense Hulusi Akar said that by July 31, the travel regulations of Turkish pilots studying at Florida and Arizona bases will be canceled and their access to the bases will be terminated. The US also refused to accept 34 pilots from Turkey, who were supposed to arrive in the country later this year, since Washington decided to suspend Turkey's participation in the F-35 program.

The suspension of the training of Turkish pilots was caused by the decision of Ankara to acquire Russian S-400 anti-aircraft missile systems. The US is actively trying to prevent Turkey from acquiring the S-400s.