Polish President Andrzej Duda said it was an “exceptionally important day for Poland’s air force and for the security of Poland and of our part of Europe.”
Defense Minister Mariusz Blaszczak signed the deal and handed the document to the U.S. envoy to Poland, Georgette Mosbacher, during a ceremony in the central town of Deblin.
Duda said it was among the biggest deals in the history of Poland’s armed forces and a sign of the strength of relations with Washington.
The U.S. State Department commended Poland’s commitment to modernizing its military, saying the aircraft “will improve Poland’s ability to provide collective and self-defense.”
Poland expects to take delivery of the F-35A Lightning II aircraft between 2024 and 2030. It will be the 10th NATO member nation to fly F-35 fighters.
Poland’s contract includes training, logistics, and simulators.
Poland’s air force already has around 50 U.S. F-16 fighter jets.
Opposition politicians have criticized the purchase as too expensive and critics say the army is not able to make full use of the capabilities of the state-of-the-art aircraft.
The opposition has also denounced the right-wing Law and Justice government for choosing the F-35 without a call for tenders.
Last year, Poland finalized a deal to buy American mobile rocket launchers worth $414 million, while in 2018 it signed a $4.75-billion contract for a U.S.-made Patriot antimissile system.