The 2019 John S. McCain National Defense Authorization Act (NDAA), signed August 13, requires the Pentagon to make explicit the overall US' strategic relationship with Turkey.
The Department of Defense has 90 days from the bill's passage, which will be mid-November, to comply with the NDAA demands. Until then, deliveries of the F-35 are on hold, however the next two jet transfers were slated for next summer anyways.
Part of the reason Congress included the provision targeting Ankara is Turkey's purchase of Russia's S-400 missile defense system, dubbed "F-35 killers." Another provision which didn't make the cut would have sanctioned Turkey for the purchase. Previously, State Department officials have told the Senate Foreign Relations Committee that they will sanction Turkey, a NATO ally equipped with US nuclear weapons, over the purchase, Sputnik News has reported.
Until the November deadline, it appears business is as usual, however. As long as Mattis and Secretary of State Mike Pompeo don't come out with a reason for blocking the jet transfers, two F-35s will fly to Turkey next summer.
Meanwhile, the jet's builders say, "Nothing's changed."
"There has been no change to our contract or our relationship with Turkey as a partner, with Turkey as a supplier," Lockheed Martin Vice President and General Manager for the F-35 program Greg Ulmer told Military.com earlier this month.
"The decision relative to the NDAA language is really government-to-government," he added.
Last July, Mattis opposed ending F-35 deals with Turkey. "At this time, I oppose removal of Turkey from the F-35 program," he wrote to lawmakers, arguing that discontinuing the trade would harm production.
Personnel at the Luke Air Force Base in Arizona, where the US trains Turkish pilots with the aircraft, say, "There has been no change to training or aircraft delivery at Luke Air Force Base," nor in "the Turkish pilot training or aircraft delivery" pending "official guidance."
A Defense Department spokesperson told Military.com that the program will continue until the report is sent to Congress.