The United States reiterated that it would defend the Philippines, and an armed attack would trigger their obligations under a 1951 treaty. This reassurance came after a recent incident in which Chinese vessels blocked and collided with two Filipino ships near the disputed Second Thomas Shoal in the South China Sea. No injuries were reported, but both Filipino vessels suffered damage.

China's sweeping territorial claims in the South China Sea are also contested by Vietnam, Taiwan, Brunei, and Malaysia. The Philippines and other countries in the region have also challenged China's vast territorial claims in the South China Sea. In response to this latest incident, the Philippine government summoned a Chinese Embassy official in Manila to file a strong protest. Defence Secretary Gilberto Teodoro said China has resorted to using "brute force," threatened the well-being of Filipino crews, and distorted facts to disguise its aggression.

The Philippines is set to raise, in talks with the Association of Southeast Asian Nations (ASEAN) over a proposed nonaggression pact to avoid major conflicts in the South China Sea, concerns over dangerous moves by China. China is hosting and holding these talks at a time when it has recently been arrogantly flouting international law.

Long before, the territorial disputes among China, the Philippines, and other nations of the region have been quarrelsome in the U.S.-China rivalry. The U.S. warned anew, invoking the commitment under the Mutual Defence Treaty of 1951 to defend the Philippines and its commitment to its allies amid China's "dangerous and unlawful actions" that obstructed a Philippine resupply mission.

The U.S. also cited in its statement a 2016 arbitration decision that invalidated most of China's claims to virtually the entire South China Sea. While Washington takes no position on the territorial disputes, it has criticized China for building islands, military installations, and other facilities on those outposts in the southeast Asian region it claims and increasing its military presence there.