The U.S. Marine Corps, Air Force, and Navy have hundreds of F-35s, both flying in the continental United States and deployed overseas, while the United Kingdom, Italy, the Netherlands, Turkey, Australia, Norway, Israel, Japan, and South Korea have smaller fleets.
The F-35 program office said the inspections should be completed in one or two days.
The decision to inspect the aircraft fuel tubes stemmed from an ongoing investigation into the F-35B crash that occurred shortly after a takeoff from the Marine Corps Air Station in Beaufort, South Carolina on September 28. If good tubes are already installed, then those planes would be returned to operational status. The Marine pilot was able to eject before the crash and did not suffer any serious injuries.
A Marine Corps F-35B was completely destroyed in a crash during training in SC on September 28.
The South Carolina crash - the first ever for the 5th-generation plane - ironically happened just a day after an F-35B successfully completed a mission in Afghanistan, an event that was reported by the Pentagon as a major milestone for the program.
The U.S. Services and global partners have temporarily suspended F-35 flight operations while the enterprise conducts a fleet-wide inspection of a fuel tube within the engine on all F-35 aircraft.
In April, a Marine Corps F-35B out the Marine Corps air station at Cherry Point, North Carolina, was forced to make an emergency landing when the aircraft fuel light came on.
Britain said the Pentagon measure did not affect all of its F-35s, and that some flying missions had been "paused", not grounded.
According to data for fiscal year 2017, the most recent available, the Air Force's F-35A models had around a 55 percent readiness rate, well below that target.
For the U.S. Defense Department, the timing could not be worse.
"F-35 flight trials from the aircraft carrier, HMS Queen Elizabeth, are continuing and the programme remains on schedule to provide our armed forces with a game-changing capability".
Britain has 16 F-35B jets and has pledged to buy 138 in total. This allows the plane to hover and land vertically like a helicopter and is a critical requirement for the Marine Corps, which often operates from amphibious ships with smaller decks than the Navy's aircraft carriers.
Other nations that have signed contracts to join the F-35 program include the UK, Italy, the Netherlands, Turkey, Canada, Australia, Denmark and Norway, according to the Pentagon.
A spokesman for the F-35s manufacturer, Lockheed Martin, said Thursday morning that industry partners were working with the F-35's Joint Program Office to investigate the problems.