On April 21st, Turkey’s Anadolu Agency reported that the US and eight other countries had abolished the 2006 deal regarding the F-35 program and signed a new agreement that has excluded Turkey.

The state outlet cited an unnamed Pentagon official.

Washington removed Turkey from the F-35 Lightning II jet program in 2019, arguing that S-400 air missile systems acquired by Turkey could be used by Russia to covertly obtain classified details on the Lockheed Martin F-35 jets and is incompatible with NATO systems.

Turkey, however, insists that the S-400 would not be integrated into NATO systems and would not pose a threat to the alliance.

Despite Turkey’s removal from the program and sanctions imposed on Turkey’s defense industry in December, the US Department of Defense said it would continue to depend on Turkish contractors for key F-35 components.

Turkey is one of the key suppliers for parts for the F-35 program.

Back in May 2020, the US Government Accountability Office (GAO) said some suppliers had struggled to meet increased production demands in 2019, and as a result, the program witnessed increased rates of late deliveries of parts due to shortages.

Excluding Turkey could potentially worsen the situation.

While the program made progress in lowering prices and increasing production, according to the GAO, about 7,000 of its more than 10,000 airframe contractors’ “key processes” do not “meet predefined design standards for ensuring product quality,” and it continues to face supply shortages that are likely to be exacerbated by Turkey’s removal.

Still “more needs to be done,” investigators wrote in the report on the production of the next-generation stealthy fighter.

“The program is at risk of missing its test schedule and not meeting manufacturing leading practices.”

“The program has identified new sources for 1,005 parts produced by Turkish suppliers, but the program is assessing the effect of 15 key parts not currently being produced at the needed production rate,” it said.

A U.S. official told the GAO that Turkish suppliers will provide parts through deliveries of the 14th production contract, or about 2022, in order to help “avoid disruptions to aircraft deliveries and additional cost growth from standing up new suppliers.”

Turkey’s Defense Industries Presidency (SSB) head İsmail Demir said the country is still producing and delivering parts for the F-35 jets despite being suspended from the program nearly a year ago.

“There was an understanding in the United States that nothing would be bought from Turkey for the F-35s after March 2020, but that approach is no longer there,” Demir said. “Our companies continue their production and delivery,” he noted, adding that Turkey remained a “loyal partner” of the F-35 program.

Taking Turkey out of the project would cost other members of the program up to $600 million, he said.

Since Turkey was de facto excluded, the $398 billion F-35 program has faced many problems since then, including engine shortages.