MANILA: The US said Thursday it has launched joint South China Sea naval patrols with the Philippines, escalating its presence as it accused Beijing of “militarising” a region which is locked in a territorial dispute

with China.

In a show of strength, US Defense Secretary Ashton Carter also announced that 275 troops and five A-10 ground attack aircraft currently in the country for annual war games will remain in the country temporarily.

The moves are likely to infuriate China, but Carter said Washington’s efforts to strengthen its military role in the region was not done “in order to provoke.”

The Pentagon chief said the US was responding to regional anxiety over China’s muscular actions in the South China Sea, including building artificial islands over disputed reefs.

“Countries across the Asia-Pacific are voicing concern with China’s land reclamation, which stands out in size and scope, as well as its militarization in the South China Sea,” Carter said. The joint naval patrols, which began last month, “contribute to the safety and security of the region’s waters,” he said after meeting with Philippines President Benigno Aquino.

Manila has been improving its defense ties with the United States to help boost its ability to defend its territory.

China claims most of the South China Sea, even waters and rocks close to the coasts of several neighbors that overlap with their claims.

Beijing has reclaimed several reefs claimed by Manila and built structures on them that the Philippines says are designed for military use — a charge China denies.

Carter announced that 275 American troops, among about 5,000 military personnel taking part in the annual Balikatan (shoulder to shoulder) war games, are to stay behind after the exercises end on Friday.

Five A-10C Thunderbolt ground attack planes and four other aircraft will also remain until the end of the month.

Some 200 of the US personnel are to train Filipino soldiers, as well as “conduct flight operations in the area, including in the South China Sea,” Carter said.

These activities will “lay the foundation for joint air patrols to complement ongoing maritime patrols,” he added.

The remainder of the US personnel will be stationed at a Manila military base on an unspecified “rotational” basis to form a “command and control” unit to support increased activities between the two allies, Carter said.

The deployments are part of a deal under which Manila has allowed American forces to rotate through five Philippine bases — some of them close to the South China Sea.