US rocket system and electronic warfare troops have for the first time taken part in exercises with Japan on the southwestern island of Amami Oshima.
A total of 2,100 personnel of Japan's Ground Self-Defense Force and the US Army have been taking part in drills across the Kyushu region since mid-August. They are simulating defense of remote islands and believed to be aiming to deter China and its maritime ambitions.
On Wednesday, media observed a Ground Self-Defense Force ground-to-ship missile deployed on the island, and the US High Mobility Artillery Rocket Systems, or HIMARS.
The forces confirmed procedures to jointly respond to enemy ships approaching the Nansei Islands.
The two countries' electronic warfare forces, which obstruct electronic waves to counter enemy attacks, confirmed procedures to coordinate with firing units.
The United States has been sending the rocket systems to Ukraine as part of its military aid.