The Philippines and the United States began an annual military exercise Monday that will include a coordinated sail in the South China Sea and other drills set in the Southeast Asia country's northern provinces, amid China's aggressive acts against Philippine vessels in the sea.

This year's Balikatan, or shoulder-to-shoulder, exercise, with nearly 17,000 Philippine and American troops participating, is the "most expansive" since its launch in 1991, said Lt. Gen. William Jurney, commander of the U.S. Marine Corps Forces, Pacific, and U.S. exercise director for Balikatan.

Troops hold hands at the opening ceremony of the Balikatan joint military exercise between the U.S. and Philippine forces at a base in Manila on April 22, 2024. (Kyodo)

Australia and France, which have beefed up defense cooperation with the Philippines, will participate in the different components of the exercise that will last until May 10, officials from the militaries of the United States and the Philippines said.

The event is set against the backdrop of an incident last month in which Chinese vessels employed water cannon against a Philippine boat, which was on a supply mission to a grounded navy ship near the Manila-controlled Second Thomas Shoal. This resulted in severe damage to the vessel and injuries to its crew members. Such aggressive actions have been recurrent since last year.

The Philippine military said the exercise is aimed at improving collaboration between the participating countries over various defense operations, including cyber defense and counterterrorism, as well as humanitarian assistance and disaster response.

Aside from a maritime drill off the western island province of Palawan facing the South China Sea, a logistics drill in the northernmost island province of Batanes and a training to counter landings by enemy forces in Ilocos Norte province in northern Luzon, among others, will take place.

Batanes, located less than 200 kilometers from Taiwan, is believed to hold strategic significance in the event of a conflict between China and the self-ruled island, which Beijing views as a renegade province to be reunified with the mainland, even by force.

Earlier this month, Manila and Washington held an unprecedented meeting of their foreign ministers, defense chiefs and national security advisers to improve coordination amid shared concerns over China.

Representatives from over a dozen countries, including Canada, Germany, India, Japan, South Korea, and some from Southeast Asia, will also participate in Balikatan as observers, according to officials.

During the 19-day exercise, two Philippine coast guard patrol vessels provided by Japan will participate for the first time in maritime drills with U.S., French and Philippine warships in waters of the South China Sea that fall within the country's exclusive economic zone.

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