Twenty-three personnel were quickly rescued following a “mishap” involving the MV-22 Osprey tilt-rotor, the primary assault support aircraft for the Marines, on Saturday.
But three marines remain missing despite a search operation supported by aircraft and ships.
“Operations have now shifted to recovery efforts. The next-of-kin for the three missing Marines have been notified,” US Marines based in Japan said in a statement.
“As the sea state permits, recovery efforts will be conducted to further search, assess and survey the area, in coordination and with assistance from the Australian Defence Force.”
The MV-22 has two engines positioned on fixed wing tips that allow it to land and take off vertically. It also has the ability to travel much faster than a helicopter.
It was in the region as part of the Australian-US joint military exercise Talisman Sabre, which has just concluded in Queensland state.