ABOARD BRP JOSE RIZAL, South China Sea, March 29, (AP): The United States, Japan and the Philippines on Friday staged joint naval drills to boost crisis readiness off a disputed South China Sea shoal as a Chinese military ship kept watch from a distance. The Chinese frigate attempted to get closer to the waters, where the warships and aircraft from the three allied countries were undertaking maneuvers off the Scarborough Shoal in an unsettling moment, but it was warned by a Philippine frigate by radio and kept away.

"There was a time when they attempted to maneuver closer but, again, we challenged them,” Philippine navy Commander Irvin Ian Robles told reporters on board the frigate BRP Jose Rizal. The latest naval drills, called the Multilateral Maritime Cooperative Activity, were opened for the first time to a small group of Manila-based media, including an Associated Press photojournalist, since such high-seas maneuvers and joint naval sails began last year.

During the daylong maneuvers, the BRP Jose Rizal, a US Navy guided missile destroyer, the DDG Shoup, and a Japanese multi-mission frigate, the JS Noshiro, sailed in formation and communicated by radio. US and Philippine helicopters flew around. A small group of American sailors from the DDG Shoup used a speedboat to transfer to the BRP Jose Rizal and hold discussions with Filipino counterparts.

"We are here to support our allies and support a free and open Indo-Pacific for everyone,” US Navy Lt. Alexander Horvath told the AP. Such naval drills result in "the vital improvements in our coordination, tactics and shared maritime awareness,” Armed Forces of the Philippines Chief of Staff Gen Romeo Brawner Jr. said in a statement.

"Every iteration strengthens our capacity to respond to maritime security challenges while reinforcing our collective ability to safeguard our national interests,” Brawner said. China claims virtually the entire South China Sea. A 2016 international arbitration ruling invalidated those claims, but Beijing refused to participate in the arbitration, rejected the outcome and continues to defy it.

The Philippines, Vietnam, Malaysia, Brunei and Taiwan have also been involved in the long-seething territorial disputes but confrontations between Chinese and Philippine coast guard and naval forces have particularly spiked in the last two years. The United States, Japan and the Philippines have been strengthening a security alliance and pressing efforts to bolster deterrence against China’s growing assertiveness in the South China Sea, a key global trade route.