China's military said it carried out a patrol in the contested South China Sea on Tuesday while the United States and the Philippines carried out their largest-ever joint military exercise.Newsweek reached out to the Philippine military and Chinese Foreign Ministry with written requests for comment.Why It MattersChina claims most of the South China Sea, despite a 2016 international tribunal decision largely dismissing those claims. Under President Ferdinand Marcos Jr., Manila has pushed back against Chinese maritime forces patrolling deeper into the Philippines' internationally recognized maritime zone.Pressure from its powerful neighbor has pushed the Philippines to pursue cruise missiles, F-16 fighter jets, and deeper defense ties with Mutual Defense Treaty ally the U.S., as well as regional partners like Japan and Australia—despite repeated Chinese warnings not to involve third countries.What To KnowThe Chinese People's Liberation Army's Southern Theater Command deployed air and naval assets on "routine patrols," command spokesperson Tian Junli said Wednesday.He sharply criticized the Philippines, accusing it of repeated provocations at sea and of conspiring with extra-regional countries to organize "so-called joint patrols"—an apparent reference to a drill involving Philippine and partner military forces.Tian said the command remained on high alert, had monitored the Philippine-hosted exercise throughout, and was committed to "safeguarding China's territorial sovereignty and maritime rights."Tuesday's drill took place within the Philippines' exclusive economic zone and featured Philippine and Australian guided-missile destroyers; Philippine Wildcat helicopters and FA-50PH fighter jets; and U.S. F-16 and F/A-18 fighters and B-1 long-range bombers, according to a statement by U.S. Indo-Pacific Command.The multilateral Maritime Cooperative Activity demonstrated the three countries' "commitment to regional security, interoperability, and multilateral cooperation," the statement said.The event was part of the 40th annual Balikatan exercise—also its largest yet—with some 12,000 U.S. and 6,000 Philippine troops participating. In addition to Australia, Japan is also taking part. The United Kingdom, France, and several other European states are attending as observers.Tensions with China have already flared over the exercise due to the U.S.'s deployment of a NMESIS anti-ship missile launcher to Philippine islands in the Luzon Strait.The strategic strait would be a key chokepoint in any U.S.-led effort to contain the Chinese navy in the event of war over nearby Taiwan. Beijing claims the self-ruled island as its territory and has dramatically ramped up military activity around it in recent years.What People Are SayingRomeo Brawner Jr., chief of staff, Armed Forces of the Philippines, was quoted in a statement: "The 9th MMCA demonstrates the growing synergy among like-minded partners in maintaining peace and stability in the Indo-Pacific. These exercises are vital in strengthening our collective defense posture and operational readiness."The U.S. Indo-Pacific Command said in a statement: "These multilateral engagements reaffirm the U.S. commitment to fostering international cooperation, maintaining maritime security, and safeguarding sovereignty for all."What Happens NextThe Balikatan exercise will wrap up on May 10.