The entire fleet of F-35 fighter jets will be retrofitted within 90 days to address an engine vibration issue, U.S. media outlets reported, citing the F-35 Joint Program Office (JPO).
The office issued a directive last week, detailing retrofit procedures for the aircraft globally.
"While only a small number of aircraft were impacted by the harmonic resonance, the plan is to retrofit the entire fleet," it said in a statement.
F-35 deliveries were halted in December 2022 after a crash involving one of the fighter jets in Fort Worth, Texas, which led to the grounding of some of the aircraft.
An investigation found a vibration issue in the engine which led to the mishap and the JPO said was a "rare occurrence" and that engineers had developed a fix for it.
The F-35, a fifth-generation stealth fighter delivered in three configurations, is the world's most expensive weapons program, with an estimated lifetime cost of 1.6 trillion U.S. dollars.
U.S. Congressman Adam Smith said in March 2021 that he thinks the F-35 is an overly expensive platform with disappointing capabilities.
"I want to stop throwing money down that particular rathole," Smith, then chairman of the House Armed Services Committee, said in a virtual event with the Brookings Institution.