The U.S. military could be granted access to more bases in the Philippines under a joint defence agreement between the two countries, the chief of the U.S. Indo-Pacific command said on Thursday after meeting the head of the Philippines armed forces.
China is likely to react negatively, having earlier this year accused Washington of "stoking the fire" when the Philippines increased the number of bases the U.S. military could use to nine.
The four additional sites approved were located close to potential flashpoints for China, as three faced north towards Taiwan and one was near the Spratly Islands in the South China Sea, where Manila and Beijing recently sparred over a disputed atoll.
U.S. Admiral John Aquilino said he and the Philippines' military chief, Lieutenant General Romeo Brawner, discussed further expanding the number of bases U.S. forces could access under the Enhanced Defense Cooperation Agreement (EDCA) and had made "recommendations to our senior leaders".
The closer U.S. defence ties with the Philippines after a period of decline has caused concern in China.
The United States says it intends to bolster an already strong alliance and improve the defence capability of the Philippines.
Brawner said the purpose of EDCA was training exercises and humanitarian and disaster response, key planks of a decades-old alliance between the two countries, and was unrelated to regional security threats.
Aquilino, who was in Manila for an annual meeting on bilateral defence cooperation, also said the allies were seeking to complete an agreement to boost intelligence sharing.
The meeting comes as the Philippines' western command flagged concerns on Thursday over a "resurgence" of Chinese fishing vessels "swarming" in waters around the Spratly islands, inside the Philippines exclusive economic zone.
The Chinese embassy in Manila said China has "indisputable sovereignty" over the Spratlys, which it calls Nansha Islands. (Reuters)