The Ministry of Foreign Affairs asked the United States not to interfere in China's domestic affairs, Foreign Ministry spokesman Hong Lei said in a news conference on Monday.
Hong's comment came amid reports that William Burns, former US deputy secretary of state, met political leaders of Taiwan, including Ma Ying-jeou and Tsai Ing-wen, in the island on Monday.
Taiwan is an inseparable part of China, and Taiwan affairs are "totally China's domestic affairs", Hong reiterated.
He requested the US "to be discreet in word and deed" and "not to interfere in any form with China's domestic affairs".
He also urged the US to observe its promise to stick to the One-China Policy and the three joint communiques it signed with China, and to oppose "Taiwan independence".
China hopes the US will "do more things that help stable development of the China-US relationship and peaceful development of the cross-Straits relationship, instead of the opposite," he added.