One of two crew members recovered after two US warplanes collided and crashed off Japan's coast early Thursday is dead and five others remain missing, the US military said.

The Marine Corps said the other recovered crew member was in fair condition.

Both were in an fighter jet that collided with a KC-130 Hercules refueling aircraft during training at about 2 am after taking off from their base in Iwakuni, near Hiroshima. The five others were in the KC-130.

The Marine Corps identified the dead crew member on Friday as Capt Jahmar Resilard, 28, of Miramar, Florida, an F/A-18 pilot with Marine All Weather Fighter Attack Squadron 242.

The Marines said in a statement that the two planes were involved in routine training, including aerial refuelling, but that it was still investigating what caused the crash.

President Donald Trump tweeted that his thoughts and prayers were with the Marine Corps crew members involved in the collision. He thanked US Forces in Japan for their "immediate response and rescue efforts" and said "whatever you need, we are here for you".

The crash took place 320 kilometres (200 miles) off the coast, according to the US military. Japanese officials said it occurred closer to the coast, about 100 kilometres (60 miles), and that's where the search and rescue mission found the two crew members.

Japan's Maritime Self-Defense Force, which dispatched aircraft and vessels to join in the search operation, said Japanese rescuers found one of the crew from the fighter jet in stable condition.

The Marines said the crew member was taken to a hospital on the base in Iwakuni and was in fair condition, but did not provide any other details.

Japan's coast guard also joined the search.

The crash is the latest in recent series of accidents involving the US military deployed to and near Japan.

Last month, a US Navy from the aircraft carrier USS Ronald Reagan crashed into the sea southwest of Japan's southern island of Okinawa, though its two pilots were rescued safely.

In mid-October, a MH-60 Seahawk also belonging to the Ronald Reagan crashed off the Philippine Sea shortly after takeoff, causing non-fatal injuries to a dozen sailors. More than 50,000 US troops are based in Japan under a bilateral security pact.

(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)