The US on March 12, 2014 accused China of raising tensions by blocking two Philippines vessels, contracted by the Philippines Navy, which were on their way to deliver supplies and troops to the disputed Second Thomas Shoal. The US said it was "troubled" by this interference with the freedom of navigation in the tense South China Sea and that countries had the right to “regular resupply and rotation of personnel” to locations before the 2002 declaration. 

US State Department spokeswoman Jen Psaki said “This is a provocative move that raises tensions. Pending resolution of competing claims in the South China Sea, there should be no interference with the efforts of claimants to maintain the status quo”. The previous day, on March 11, the Philippines summoned China’s charge d’affaires, accusing Beijing of a “clear and urgent threat” to Manila’s interests. Beijing countered that the ships “infringed China’s territorial sovereignty” and violated a 2002 declaration of conduct in the South China Sea.

The Second Thomas Shoal, which sits around 200 kilometers (125 miles) from the western Philippine island of Palawan, is claimed by the Philippines, China and Taiwan. Beijing calls it Ren’ai Reef.