China has made serious demarches to the United States over Taiwan leader Tsai Ing-wen's planned "transit" through the US, Foreign Ministry spokesman Wang Wenbin said on Tuesday, urging the US to cut official exchanges with the region.

Tsai will "transit" through New York and Los Angeles during her trip to and from Guatemala and Belize from March 29 to April 7.Reports have said Tsai may meet US House Speaker Kevin McCarthy in California.

In response, Wang said at a daily news conference that Tsai is trying to promote "Taiwan independence "under the guise of the "transit".

China is resolutely against official exchanges between the US and the Taiwan region in any form, Wang said.

China also firmly opposes any US visit made by leaders of the Taiwan authority in any name and under any pretext, as well as the US violating the one-China principle by having contact with the Taiwan authority in any form, the spokesman said.

Wang urged the US to observe the one-China principle and the stipulations in the three China-US joint communiques, and deliver on the US leadership's commitment of not supporting "Taiwan independence", "two Chinas" or "one China, one Taiwan".

The US should stop official interaction with Taiwan in any form, stop upgrading its substantive exchanges with the region, and stop obscuring and hollowing out the one-China principle, Wang said.

"'Taiwan independence' will lead to a dead end. Any attempt to collude with external forces to seek 'Taiwan independence' is doomed to fail," the spokesman warned the Taiwan authority. "China will firmly safeguard its sovereignty and territorial integrity."

China voiced its "grave concerns "and lodged serious representations with the US earlier this month, when reports came out that McCarthy planned to meet Tsai in California "in coming weeks" during Tsai's "transit".