The U.S. and the Philippines kick off the largest version of their flagship military exercise in more than 30 years on Tuesday, a high-profile display of their renewed alliance that comes just a day after China was set to conclude its own drills around Taiwan.

The annual Balikatan exercise will focus on developing maritime security and amphibious operations, and will include live-fire training, at a time when the two nations are seeking to push back against Chinese aggression in the South China Sea. The presence of more than 17,600 military personnel almost doubles last year’s level, according to the U.S. Embassy in Manila.

The size of the drills marks the culmination of U.S. efforts to restore ties with the Philippines under President Ferdinand Marcos Jr., whose predecessor, Rodrigo Duterte, often snubbed Washington in favor of Beijing.