The Typhon system, which can be equipped with cruise missiles capable of striking Chinese targets, was brought in for joint exercises earlier this year, both countries said at the time, but has remained there.
China and Russia have condemned the first deployment of the system to the Indo-Pacific, accusing Washington of fueling an arms race.
The deployment, some details of which have not been previously reported, comes as China and U.S. defense treaty ally the Philippines clash over parts of the hotly contested South China Sea.
Philippine officials said Filipino and U.S. forces continued to train with the missile system, which is on the northern island of Luzon, facing the South China Sea and is close to the Taiwan Strait.
A Philippine army spokesman, Colonel Louie Dema-ala, on Wednesday said training was ongoing and it was up to Philippine authorities and the United States Army Pacific to decide how long the missile system would stay.
Persons:
Ezra Acayan, Lin Jian, Louie Dema, USARPAC, Ferdinand Marcos Jr
Organizations:
High Mobility Artillery, Getty, United States Army Pacific, Reuters, Philippine
Locations:
Philippines, Laur, Nueva Ecija, States, U.S, Asia, Taipei, China, Russia, Washington, Luzon, Taiwan Strait, Philippine