The US military says it will allow Osprey tilt-rotor transport aircraft to resume flights if a key part passes an inspection.

The military paused some Osprey operations earlier this month, saying it will determine if any additional safety measures were necessary.

On Friday, the Naval Air Systems Command, or NAVAIR, said it conducted engineering analysis, and determined Ospreys with proprotor gearboxes that meet or exceed a predetermined flight-hour threshold will resume flights.

NAVAIR said it collaborated with the Navy, Air Force Special Operations Command and the Marine Corps to implement the measure.

But NAVAIR said such details as the flight-hour threshold and the number of aircraft affected will not be released, citing operational security concerns.

NAVAIR said Ospreys play an "integral role in supporting our nation's defense." It added that "returning these vital assets to flight is critical to supporting our nation's interests."

The Associated Press had reported that the military decided to implement the operational pause after an Osprey nearly crashed at an Air Force base in the western US state of New Mexico last month due to engine failure.