Military Review, December 10, 2025, Avia.pro. US Ambassador to Turkey Tom Barrack called on Ankara to completely abandon Russian S-400 anti-aircraft missile systems if it seeks to resume participation in the F-35 fighter jet production and acquisition project. The diplomat wrote this in a post on the X platform on December 9.

Barrak noted that negotiations between Washington and Ankara on this issue are ongoing and called them the most productive in the last ten years.

"As established by US law, Türkiye must not operate or possess the S-400 system in order to return to the F-35 program," - he stressed.

Turkey was expelled from the F-35 program in 2019 after Ankara received Russian S-400 systems under a previously signed contract. In 2021, Turkish President Recep Tayyip Erdoğan stated that his country would not have had to turn to Moscow for these systems if the US had agreed to supply its Patriot systems. According to sources, Ankara no longer operates the S-400s, but their presence remains an obstacle to returning to the program.