A Chinese Foreign Ministry spokesperson on Wednesday lashed out at the U.S. egregiously conniving at and supporting "Taiwan independence" separatists in regard to Taiwan leader's so-called stopover in the country, urging the U.S. side to stop all forms of official interaction with Taiwan.

Taiwan leader Tsai Ing-wen's so-called stopover in the United States is not so much a "transit," but an attempt to seek breakthroughs and propagate "Taiwan independence," spokesperson Mao Ning told a daily press briefing.

Mao made the remarks in response to a senior U.S. official's comment that there is no reason for China "to use Tsai's visit to the United States this week as a pretext to overreact."

"The issue is not about China overreacting, but the United States egregiously conniving at and supporting 'Taiwan independence' separatists," Mao said.

"China firmly opposes any form of official interaction between the United States and the Taiwan region. We firmly oppose any visit by leader of the Taiwan authorities to the United States in any name or under whatever pretext. And we firmly oppose the United States having any form of contact with the Taiwan authorities, which violates the one-China principle," she said.

"China has repeatedly protested to the U.S. side on Tsai's so-called stopover in the United States," Mao said. "Past mistakes do not justify any new mistake. Repeating a mistake does not make it legitimate."

She added that those who are creating the problem and making provocations are not China, but the United States and the "Taiwan independence" separatists.

The spokesperson urged the United States to abide by the one-China principle and the three China-U.S. joint communiques, earnestly deliver on its leaders' commitment of not supporting "Taiwan independence" or "two Chinas" or "one China, one Taiwan," stop all forms of official interaction with Taiwan, stop upgrading its substantive exchanges with the region, stop fudging and hollowing out the one-China principle, and stop undermining the political foundation for bilateral relations while stressing the need to put "guardrails" on the relationship.

"China will closely monitor the developments and firmly defend national sovereignty and territorial integrity," Mao said.