Despite opposition from Congress, Turkey will receive its first F-35 Joint Strike Fighter jets from the Pentagon's top weapons supplier on Thursday.
Following a formal handoff ceremony at Lockheed Martin's F-35 facility in Fort Worth, Texas, the defense giant will ferry the aircraft to Luke Air Force Base in Arizona where Turkish pilots will begin training alongside U.S. airmen.
The two fifth-generation jets are the first of what the NATO member and F-35 program partner hopes will be the start of a 100-strong fleet.
However, both House and Senate versions of the 2019 National Defense Authorization Act contain restrictions on Turkey's participation in the F-35 program due to Ankara's plan to buy Russia's advanced S-400 air defense system.
On Tuesday, the Senate voted 85 to 10 to block the sale, citing the deal with the Russians as well as Turkey's continued detention of American pastor Andrew Brunson, who was accused of spying and attempting to overthrow the government in 2016. He has denied all charges.
Turkish Prime Minister Binali Yildirim called the Senate vote "lamentable," describing it as against the spirit of NATO. He added that his country was "not without alternatives."
The Russian-made missile system, which is equipped with eight launchers and 32 missiles, is capable of targeting stealth warplanes like the F-35 fighter.
"The Turkish government claims to have purchased a Russian air defense system designed to shoot these very planes down," Sen. Jeanne Shaheen, D-N.H., said last week on the Senate floor. "We would be handing this technology over to the Kremlin if we granted Turkey these planes, and Congress will not stand for it."