Japanese defense officials are searching for a fighter jet off the coast of Aomori Prefecture, northern Japan. They lost contact while it was on a training mission.

Japanese Defense Minister Takeshi Iwaya said, "At around 19:27 Tuesday, an F-35A from the Air Self-Defense Force Misawa air base lost radar contact 135 kilometers east of the coast during training."

Iwaya said the one pilot on board is missing. Officials say the jet was flying with three other planes of the same model, and there were no reports of problems before contact was lost.

The Self-Defense Forces and the Coast Guard have dispatched patrol aircraft and ships to search for the jet.

The F-35 was jointly developed by the United States and eight other countries. Its stealth capabilities make it difficult to detect by radar.

Thirteen F-35As are currently based at Misawa Air Base. It's set to become Japan's next-generation mainstay fighter.

Iwaya says the other 12 jets will be grounded for the time being.