The two-day military exercise involved naval and air force units from the Philippines, Canada, the United States and Australia amid growing security challenges in the region.

"This multilateral maritime cooperation exercise will be the first to be organized as a group among the four countries and will involve naval and air force units," a Philippine military spokesman told AFP.

The four countries said the exercise will take place within the Philippines' 200-nautical mile exclusive economic zone to enhance cooperation and interoperability among their armed forces, and demonstrate their shared commitment to strengthening regional and international cooperation in support of a free and open Indo-Pacific.

"Australia, Canada, the Philippines and the United States uphold freedom of navigation and overflight and other lawful uses of the sea and airspace, and respect for maritime rights under international law, as reflected in the United Nations Convention on the Law of the Sea," AFP quoted the joint statement of the four countries as saying.

Last week, the Philippines also held bilateral naval exercises with the United States and later with Japan in the South China Sea. In April, Australia participated in a similar exercise with the Philippines, the United States and Japan.