Red-faced US military officials say they have finally found debris from an F-35 military jet that went missing after the pilot ejected over South Carolina.

The mishap began after pilot of the F-35B Lightning II jet ejected safely from the aircraft on Sunday (local time), according to a military statement.

But the $US100 million ($155 million) plane then went into “zombie” mode and kept on flying – prompting an embarrassing plea from the US top brass.

“If you have any information that may help our recovery teams locate the F-35, please call the Base Defence Operations Centre at 843-963-3600,” Joint Base Charleston wrote on social media platform X (formerly Twitter).

The fighter jet’s main advantages, according to its manufacturer Lockheed Martin, are that it is nearly impossible to track with radar and is packed with advanced sensors and other gear.

JJ Gertler, a senior analyst at defence consultancy Teal Group said it was possible that when the pilot ejected, the plane’s electronics “were fried and thus the military was no longer able to track its location.”

He told the BBC it was possible the aircraft kept flying, but that it was “extremely unlikely” due to “the damage the aircraft would have received from the ejection seat” and “the change in aerodynamics when the canopy is gone”.

The embarrassing admission led to widespread mockery online.

“How in the hell do you lose an F-35?” tweeted Republican congresswoman for South Carolina, Nancy Mace.

“How is there not a tracking device and we’re asking the public to what, find a jet and turn it in?”

Meanwhile, other users leapt to advice the US military:

“This whole mess with the missing F35 could have been avoided if you put an AirTag, on it guys,” wrote one X user.

Tweet from @TheBabylonBee

“BREAKING: F-35 stealth fighter jet found in Mar-a-Lago bathroom,” wrote another.

Added one: “F35 expert here! this is not funny, F35s only do this when they’re in extreme distress.”

Tweet from @wyatt_privilege

In a follow-up statement on Monday, military officials said debris had been found in rural Williamsburg County, “two hours north-east of Joint Base Charleston”.

Officials had focused their searches around Lake Moultrie and Lake Marion, north of the city of Charleston – the jet’s last known location.

The debris found has been confirmed as the wreckage of the missing plane.

“The mishap is currently under investigation, and we are unable to provide additional details to preserve the integrity of the investigative process,” the US Marine Corps said on Monday after the search ended.

-with AAP