Beijing is calling the presence of an American destroyer near a sensitive archipelago in the South China Sea "a serious political and military provocation."
The statement about the USS Stethem, a guided-missile destroyer that was steaming near Triton Island in the Paracels, an island chain claimed by China, came hours before President Trump and Chinese leader Xi Jinping spoke by phone about "negative factors" affecting relations between the two countries.
Beijing reportedly sent fighter planes and warships to the waters near Triton in response to the presence there of the Stethem.
The Pentagon has routinely defended the deployment of U.S. warships to the region, which has become increasingly tense in recent years, as exercises in "navigation freedom." China, however, has decried U.S. interference in what it insists are its territorial waters. Beijing's expansive claims in the region have also periodically put it at odds with its maritime neighbors.
In a statement released by the Chinese government on Sunday, Foreign Ministry spokesperson Lu Kang said the U.S. behavior "violated the Chinese law and relevant international law, infringed upon China's sovereignty, disrupted peace, security and order of the relevant waters and put in jeopardy the facilities and personnel on the Chinese islands, and thus constitutes a serious political and military provocation. The Chinese side is dissatisfied with and opposed to the relevant behavior of the US side."
U.S. Pacific Fleet spokesman Lt. Cmdr. Matt Knight responded: "U.S. forces operate in the Indo-Asia-Pacific region on a daily basis, including in the South China Sea. All operations are conducted in accordance with international law and demonstrate that the United States will fly, sail, and operate wherever international law allows. That is true in the South China Sea as in other places around the globe."