Naval vessels from the Philippines and United States conducted a joint sail through parts of the South China Sea lying within the Southeast Asian nation's exclusive economic zone, Manila's military said on Monday.
It was the first time the Philippines and Washington have carried out a joint sail in waters west of Palawan island, the Armed Forces of the Philippines' Western Command said.
The display of cooperation between the U.S. and Philippines comes at a time of heightened tension between Manila and Beijing, which claims much of the South China Sea.
The Philippine Navy's guided-missile frigate BRP Jose Rizal and the US Navy Alrleigh Burke-class guided missile-destroyer USS Ralph Johnson participated in the joint sail, during which ships practice manoeuvring near other vessels.
"This event aims to provide an opportunity for the Philippine Navy and the U.S. Indo-Pacific Navy to test and refine existing maritime doctrine," the Western Command said in a statement.
Manila has repeatedly complained against what it described as China's "aggressive" actions in the South China Sea, including the use of a water cannon by its coast guard against a Philippines vessel engaged in a resupply mission on Aug. 5.
China has built militarised, manmade islands in the South China Sea and its claim of historic sovereignty overlaps with the exclusive economic zones of the Philippines, Vietnam, Malaysia, Brunei and Indonesia.
The Philippines won an international arbitration award against China in 2016, after a tribunal said Beijing's sweeping claim to sovereignty over most of the South China Sea had no legal basis.
