"Unfortunately, Turkey's decision to purchase Russian S-400 air defense systems render its continued involvement with the F-35 impossible," White House Spokesperson Stephanie Grisham said.
She added that the U.S. program cannot be used at the same time with the Russian intelligence collection platform.
U.S. Undersecretary of Defense for Acquisition and Sustainment Ellen Lord also commented on such decision.
"We are proceeding with a very orderly wind-down by March 2020. This is a specific response to a specific action”.
Earlier, the United States announced a possible termination of military cooperation with Turkey, if Ankara does not refuse to buy Russian S-400 missile defense systems. In particular, Commander-In-Chief of the US Forces in Europe and the combined NATO forces in Europe said the United States could refuse to supply F-35 fighters to Turkey.
In April, it was reported that the United States decided to stop supplying Turkey with spare parts for F-35 fighters as Ankara plans to buy the Russian S-400 missile defense system.
The United States has repeatedly warned Turkey that the Russian S-400 system, which Ankara intends to acquire, will jeopardize the safety of the F-35 aircraft manufactured by Lockheed Martin. Ankara, which is a partner in the creation of the stealth aircraft, said it would not take this step.
In September 2017, Ankara announced the conclusion of a contract with Russia on the purchase of two S-400 air defense missile systems at the beginning of 2020. Five months later it became known that the Russian Federation began the production of systems for Turkey. In Febuary 2019, the head of the Turkish defense industry department Ismail Demir said that deliveries of two S-400 anti-aircraft missile systems would begin in July 2019. Turkey plans to put them into service by October 2019.