"The exercise will consist of field training events to include basic infantry skills training, vertical assaults integrated with MV-22B Osprey flight operations, and combined-arms operations", the release said on Tuesday.
PACOM explained that more than 145 Okinawa-based US Marines from Battalion Landing Team, 31st Marine Expeditionary Unit, joined about 500 Japan Ground Self Defence Force counterparts for the 18-31 January exercise.
The 31st Marine Expeditionary Unit - the Marine Corps' only continuously forward-deployed unit - serves as the primary US crisis response force in the Indo-Pacific region.