China has asked the Philippines to avoid being "taken advantage of" by the United States after the Southeast Asian nation agreed to give US military forces access to four new bases.
A statement by the Chinese embassy in Manila said Thursday's announcement by the Philippines and US was responsible for escalating tensions.
"China always holds that defence and security cooperation between countries should be conducive to regional peace and stability, not targeted against any third party, even less to harm the interests of a third party," the embassy said.
"The United States, out of its self interests and zero-sum game mentality, continues to step up military posture in this region. Its actions escalate regional tension and undermine regional peace and stability."
The statement expressed the hope that "the Philippine side stays vigilant and resists being taken advantage of and dragged into troubled waters".
The bases deal was announced during US Defence Secretary Lloyd Austin's visit to the Philippines, as part of his Asia tour aimed at countering rising China's influence in the region.
In a joint statement, defence officials said the two countries planned to "accelerate the full implementation of the Enhanced Defence Cooperation Agreement (EDCA) with the agreement to designate four new agreed locations in strategic areas of the country".
The US military already has access to five sites in the Philippines, including the Cesar Basa airbase and Fort Magsaysay near Manila. There are also bases in central Cebu, Palawan and in the country's south.
While the new sites have not been identified, it has been widely reported that most will be on the main island of Luzon - the closest Philippine land mass to Taiwan - where the US already has access to two locations.
The fourth will reportedly be on the western island of Palawan, which faces the Spratly Islands in the hotly contested South China Sea, taking the number of sites there to two.
Austin said he and acting defence secretary Carlito Galvez "discussed concrete actions to address destabilising activities in the waters surrounding the Philippines".
"We remain committed to strengthening our mutual capacities to resist armed attack," he said.
Rivalry between China and the US is intensifying in the region, where concerns are growing over China's military deployments in the East and South China Seas.
In addition to ongoing sovereignty disputes between Beijing and its neighbours, there are also worries that countries in the region will be forced to choose between the two big powers.
US officials said Washington is helping its regional allies to stand up to coercion by China, but Beijing accuses the US of provoking regional tensions by sending military aircraft and vessels to the region.
Beijing has also said that US security initiatives in the region are damaging to regional peace.
