The Philippines on Saturday wound up a series of joint maritime exercises with the United States and Japan, against a backdrop of tension between Philippine and Chinese vessels at two disputed features.

The 17th Multilateral Maritime Cooperative Activity, which began on July 21, brought together warships, coast guard vessels, and surveillance and fighter aircraft, the Armed Forces of the Philippines (AFP) said in a statement yesterday.

“Throughout the five-day activity, participating forces carried out a series of advanced maritime interoperability exercises,” the AFP said. These included communication exercises, replenishment at sea operations, and division tactics.

The exercises underscored “the enduring partnership among the partner nations in promoting peace, stability, and security in the Indo-Pacific region,” it stated. They also reflected the AFP’s “continuing commitment in ensuring freedom of navigation and overflight while deterring illegal, coercive, aggressive, and deceptive activities” in the South China Sea. The Philippine military did not disclose the exact location of the exercises.

The drills took place at a time of resurgent tensions in the contested seaway, which have coincided with the 10th anniversary of the South China Sea arbitral ruling, handed down by a special tribunal in The Hague, that found China’s expansive “nine-dash line” claim in the South China Sea had no basis under international law. China does not recognize the ruling, saying that it is “null and void.”