an opening ceremony in Taipei on June 12, 2018. Beijing (CNN)China has lodged a protest with the US following the official opening of Washington's new de facto embassy in Taiwan, a self-ruled island off China's southeastern coast that Beijing considers a renegade province. "The United States sending officials to Taiwan under any excuses is in serious violation of the 'one China' principle," Geng Shuang, a Chinese foreign ministry spokesman, said Tuesday. "It interferes with China's internal affairs and negatively impacts China-US relations."