China has condemned a meeting between Taiwan's Tsai Ing-wen and the speaker of the US House of Representatives, Kevin McCarthy, in California.

"We firmly oppose all forms of official interaction between the United States and Taiwan and any visit by leader of the Taiwan authorities to the United States in any name or under whatever pretext," a Defence Ministry statement said.

"We urge the US side to honour its solemn political commitment made to China on the Taiwan question. The US side must stop its blatant interference in China's internal affairs, and stop its official interaction with Taiwan."

The Defence Ministry also said the PLA "will stand by its responsibility and mission and always keep on high alert" to help safeguard China's sovereignty as well as peace and stability across the Taiwan Strait.

A Foreign Ministry spokesperson, meanwhile, said cross-strait ties were severely strained with Tsai refusing to recognise the 1992 consensus, which embodies the one-China principle, and supporting "Taiwan independence".

The Taiwan Work Office of the Party Central Committee also slammed the meeting during Tsai's stopover in the US after her visit to Guatemala and Belize.

"Taiwan leader Tsai Ing-wen on Thursday met with US House Speaker Kevin McCarthy during the former's so-called 'transit' through the United States. This is another provocative move from Taiwan's Democratic Progressive Party authorities to further collude with the United States and 'cling to US support to seek independence'," a statement read.

More than a dozen Democratic and Republican lawmakers joined McCarthy, a Republican, for the talks with Tsai. (Additional reporting by Xinhua, AP)