The US has already told Japan about the reorganisation, which it will announce after a two-plus-two meeting in Washington on Wednesday between Japan’s ministers of defence and foreign affairs and their US counterparts, the paper reported.

Officials at Japan’s defence ministry were unavailable for comment. A foreign ministry official declined to comment about the report, but said Japan and the US “will discuss matters regarding issues on the US Forces Japan, including the realignment of the US Forces Japan”.

The creation of the new units, called Marine Littoral Regiments, is part of a major reorganisation of the US Marine Corps outlined by its commandant, General David Berger, in 2020 in his Force Design 2030 paper.

At the time Berger told Reuters he wanted those units to work closely with Japan’s Self Defense Forces to prevent easy access to the Pacific for China’s military.

As part of that plan, the Marines are cutting aircraft numbers, and dumping most of their cannon artillery and heavy armour in favour of smaller “dispersed” forces equipped with missiles and drones that can operate in contested areas.

Japan hosts 18,000 US Marines, the biggest concentration outside the United States. Most of them are in bases on the main Okinawan island, which is part of a chain that stretches along the edge of the East China Sea to within about 100 km of Taiwan.

That large US military presence has fuelled local resentment, with Okinawa’s government asking other parts of Japan host some of the force. Although reorganisation may not increase the number of Marines in Okinawa, dispersing them could mean a broader presence along the island chain.