The $716 billion John S. McCain National Defense Authorization Act for Fiscal Year 2019 (NDAA) prohibits the sale of F-35 aircraft to Turkey for 90 days. Within that period, the Pentagon must produce a report on the risks entailed by NATO-member Turkey purchasing the Russian S-400 missile defense system.
Turkey received its first pair of a projected 100 aircraft batch in June. The fighter jets remain in the U.S. while their Turkish pilots are trained. Delivery will not take place before September 2019.