The Ground Self-Defense Force and the U.S. Marine Corps have started a three-weeklong amphibious exercise to improve response capabilities to contingencies as China expands its maritime strength and reach.

The drill, due to run through March 25 in central Japan, is the "first large-scale" exercise in the Indo-Pacific region between the GSDF's amphibious brigade and the 31st Marine Expeditionary Unit, according to Capt. Nikki Gallegos.

Gen. Yoshihide Yoshida, the GSDF chief of staff, told a news conference earlier this month that the training, involving about 400 GSDF members and 600 from the Okinawa-based Marine unit, is "important to enhance interoperability" between the two forces.