The commandant of the US Marine Corps says it plans to deploy a Marine Littoral Regiment to Guam in a few years.
General Eric Smith spoke to reporters in Washington on Friday about the plan.
The Marine Corps regards MLRs as a pillar of the corps' reorganization.
The first MLR was set up in Hawaii in 2022 against the backdrop of the Chinese military's growing missile capabilities. Last November, another unit was set up in Okinawa, southern Japan.
The MLRs deploy small units to remote islands where, in the event of an emergency, they carry out reconnaissance and stage attacks within the range of the enemy's missiles.
Smith said the MLR in Guam "will have responsibility to rapidly deploy inside the first island chain into the Philippines."
The first island chain refers to areas between Japan's Nansei Islands and the Philippines, including Taiwan.
He said that if China was to attack the Philippines or Japan, then "it would be a very bad day" for it.
Smith spoke about a plan to move about 4,000 Marines from Okinawa to Guam based on an agreement with Japan. He said the Marine Corps will begin the transfer by December.
Smith also said the US is working with the Japanese government on the mutual use of facilities on Okinawa's Ishigaki Island and elsewhere.