Japan has lost contact with one of its F-35 stealth fighters.

The jet was flying east of northern Japan when it disappeared from radar.

TOKYO (Reuters) - Japan's military said on Tuesday it lost contact with one of its Lockheed Martin F-35 stealth fighters over the Pacific Ocean close to northern Japan.

Japan's first squadron of F-35s has just become operational at the Misawa air base and the government plans to buy 87 of the stealth fighters to modernize its air defenses as China's military power grows.

The advanced single-seat jet was flying about 84 miles east of the air base in Aomori Prefecture at about 7:27 p.m. (1027 GMT) on Tuesday, when it disappeared from radar, the Air Self Defense Force said.

The military has launched a search for the missing aircraft and its pilot, it said in a statement.

US Marine Corps F-35Bs land on the USS America. Lockheed Martin

A crash would be only the second time an F-35 has gone down since the plane began flying almost two decades ago. It would also be the first crash of an A version of the fifth-generation fighter designed to penetrate enemy defenses by evading radar detection.

A US military short take off and landing (STOVL) F-35B crashed near the Marine Corps Air Station Beaufort in South Carolina in September prompting a temporary grounding of the aircraft. Lockheed Martin also makes a C version of the fighter designed to operate off carriers.

Japan's new F-35s will include 18 short takeoff and vertical landing (STOVL) B variants that planners want to deploy on its islands along the edge of the East China Sea.

(Reporting by Tim Kelly, Kiyoshi Takenaka and Stanley White; editing by Darren Schuettler)