Summary US blocked Turkey from F-35 program for buying Russian S-400 SAM system, hinting at potential readmission if S-400s are given up. Gulf States like UAE, Saudi Arabia, Qatar desire F-35s, facing approval challenges amid Israel's opposition and other regional tensions. Thailand denied US F-35 purchase due to training and technical issues, Taiwan interested but met with resistance over Chinese tensions and espionage fears.

The F-35 Lightning II is arguably the most advanced fighter jet on the international market (there are export restrictions on the F-22 Raptor). The F-35 has been purchased by dozens of US allies worldwide , but the US does not just sell the jet to any country. Some countries would like to purchase the F-35, but the United States has blocked the sales for various reasons (the countries below are not an exhaustive list).

The US is very protective of the F-35 fighter jet and does not want to see it compromised - although it does permit some countries to produce the F-35 locally under license . Turkey Perhaps the most famous and high-profile example of the US blocking the F-35's sale is to Turkey. Turkey is a NATO member and key ally and partner of the United States in the region.

Turkey also hosts a major US Air Force base at Incirlik Air Base (which is home to the 39th Air Base Wing and US tactical nuclear weapons). Turkey was part of the F-35 program and purchased F-35s, the first of which had been built and were ready to be delivered to Turkey in 2018. .