The exercise aims to boost Manila’s military capability while serving as a US show of support for its Asian ally amid China’s growing assertiveness.
Nearly 18,000 troops are taking part in the annual exercises, which for the first time will include the sinking by live fire of a decommissioned Philippine navy warship in the South China Sea, waters that Beijing claims almost entirely.
It follows a deal announced last week for US forces to use an increased number of bases in the Philippines, including one near Taiwan.
The exercises and growing US access to Philippine bases have angered China.
“Facts speak louder than words. Judging from the locations of the new military bases, the intention behind those sites is more than obvious,” Chinese foreign ministry spokesman Wang Wenbin told reporters in Beijing on Wednesday.
He warned: “We would like to once again remind the relevant country in the region that pandering to forces outside the region will not bring greater security, but will cause tensions, put regional peace and stability at risk, and eventually backfire.”
Balikatan will include military helicopters landing on a Philippine island off the northern tip of the main island of Luzon, nearly 300km from Taiwan, and the retaking of another island by amphibious forces.
It will be the first time the exercises have been held under President Ferdinand Marcos, who plans to watch the ship sinking on Apr 26.
He has sought to strengthen ties with the United States after his predecessor Rodrigo Duterte weakened the alliance.