The U.S. on Wednesday said Turkey's further participation in the F-35 program is "impossible" due to its procurement of the Russian S-400 air defense system.
"Turkey's decision to purchase Russian S-400 air defense systems renders its continued involvement with the F-35 impossible," White House spokeswoman Stephanie Grisham said in a statement. "The F-35 cannot coexist with a Russian intelligence collection platform that will be used to learn about its advanced capabilities."
The Trump administration had threatened to expel Turkey from the F-35 fighter program if it acquired the S-400 from Russia, warning the anti-air system could be used by Moscow to covertly attain secret information on the stealth fighter.
The delivery of S-400 components began last week and is ongoing with 14 shipments of related equipment so far having landed in Turkey over last six days.
The Pentagon is expected to brief reporters later Wednesday on additional details regarding the White House's announcement.
Grisham stressed that as NATO allies, the U.S. and Turkey share a relationship that is "multi-layered, and not solely focused on the F-35."
"Our military-to-military relationship is strong, and we will continue to cooperate with Turkey extensively, mindful of constraints due to the presence of the S-400 system in Turkey," she said.
Following protracted efforts to purchase an air defense system from the U.S. with no success, Ankara signed a contract in 2017 to purchase the S-400s from Russia.
U.S. President Donald Trump blamed the ongoing row over the F-35 on the Obama administration, whom he said created the problem by not allowing the Turkish government to purchase Patriot missile systems.
"As soon as they found out that they were going to have to buy the missiles, comparable missiles, not as good a missile, but a comparable almost missile from Russia - all of a sudden everybody started rushing and saying to Turkey, 'Okay, we'll sell you the Patriot missile,'" he told reporters at the White House Tuesday.
