Two sources, who are familiar with Turkey's role in the F-35 program and who spoke on condition of anonymity with Reuters, did not say a final decision had been made, yet such a move is being seriously considered as the two NATO allies have been at odds for months over Turkey's order for the Russian S-400 defence system.
Turkish pilots are currently training at Luke Air Force Base in Arizona. It was unclear whether a decision to suspend their training would mean they would also have to leave the country, or if they would remain at the base until a final decision is made about Turkey's future in the F-35 program.
The Pentagon and State Department declined to comment, however, the US has previously said that Turkey cannot have the S-400 and be part of the F-35 program. It has also warned that if Turkey receives the delivery of the Russian system, it would trigger US sanctions under CATSAA, a law that imposes sanctions against countries procuring military equipment from Russia.