The US is "deliberately [stirring] up troubles" in the South China Sea, a rep from China's Foreign Affairs Ministry said Sunday in a statement, referring to an incident it's calling a "serious political and military provocation." Per the BBC, that alleged provocation was the USS Stethem warship sailing within 12 nautical miles of Triton Island, a disputed piece of land located in the Paracel Islands (the Chinese refer to the archipelago as the Xisha Islands). Although a US defense official tells the AP the ship was simply carrying out a "right of innocent passage" exercise near the island—which is claimed not only by China, but also by Vietnam and Taiwan—the Chinese responded by dispatching military vessels and fighter planes to the area.
The ship's presence "violated the Chinese law and relevant international law, infringed upon China's sovereignty, disrupted peace ... and put in jeopardy the facilities and personnel on the Chinese islands," the ministry rep noted. Twelve nautical miles is an internationally agreed-upon territorial limit, meaning the Stethem's voyage indicates the US doesn't recognize China's claim on the island, Reuters notes. The AP reports that, in a Monday phone call, Chinese President XI Jinping told President Trump "some negative factors" were damaging the US-China relationship. That call was not only preceded by the Stethem incident, but also by US sanctions on a Chinese bank with North Korea ties and sour feelings from the US selling arms to Taiwan, per the AP. (Are there weapons on China's man-made islands?)