US-Turkey defense ties center on the 2020 CAATSA sanctions imposed after Ankara acquired Russia’s S-400 system, which also excluded Turkey from the F-35 program under separate NDAA restrictions. President Trump has repeatedly signaled intent to lift the measures, citing his personal relationship with President Erdoğan and stating at the July 2026 NATO summit in Ankara that sanctions on friends should end. As of early October 2026, Trump reiterated no obstacles exist and expressed willingness to accommodate Ankara, while Turkish Deputy Defense Minister Alpaslan Kavaklıoğlu voiced optimism in mid-October about imminent relief and progress on six stored F-35s through intensive Washington talks. US Secretary of State Marco Rubio has noted that S-400-related conditions must still be addressed for any F-35 transfer. Any waiver would likely require presidential certification and congressional review, with outcomes tied to bilateral negotiations and potential creative resolutions on the S-400 issue.