In a strongly worded statement issued on November 19, the US State Department stated that "Two days ago, the People’s Republic of China (PRC) Coast Guard blocked and used water cannons against Philippine resupply ships en route to Second Thomas Shoal in the South China Sea. The United States stands with our ally, the Philippines, in the face of this escalation that directly threatens regional peace and stability, escalates regional tensions, infringes upon freedom of navigation in the South China Sea as guaranteed under international law, and undermines the rules-based international order". It cautioned the PRC not to "interfere with lawful Philippine activities in the Philippines’ exclusive economic zone" and added "The United States stands with our Philippine allies in upholding the rules-based international maritime order and reaffirms that an armed attack on Philippine public vessels in the South China Sea would invoke U.S. mutual defense commitments under Article IV of the 1951 U.S. Philippines Mutual Defense Treaty. The United States strongly believes that PRC actions asserting its expansive and unlawful South China Sea maritime claims undermine peace and security in the region".

(Comment: The statement is unusually strong and raises the possibility that the U.S. would have to use force against China. It is in sharp contrast to the passivity shown by the Obama Administration.)