The United States has doubts Iran will be able to make use of the highly sophisticated technology found in a stealth drone that crashed in Iran during a reconnaissance mission, a US official said Wednesday.

The RQ-170 Sentinel high-altitude stealth drone was on a surveillance mission when it crashed in eastern Iran, weekend news reports said.

But even if Iran succeeds in recovering some technology from the wrecked aircraft, Tehran is unlikely to be able to make use of it, said a US official who declined to be named.

"US capabilities are remarkably advanced, and it's unclear that the Iranians have the expertise" to exploit the advanced know-how in the aircraft, the official said.

Washington nevertheless is "concerned" about the loss of the top secret drone, a senior military official told reporters.

"We're always concerned when there's an aircraft, whether it's manned or unmanned, that we lose -- particularly in a place where we're not able to get to it," Navy Captain John Kirby said Tuesday.

NATO has denied a claim by Tehran that the drone crashed after it succeeded in shooting it down.

US officials said that aircraft had been en route to Afghanistan at the time of the crash.

An identical stealth aircraft to the one lost in Iran reportedly was used by US Navy SEALs in the operation last May that killed Osama bin Laden in Pakistan.