WASHINGTON/TAIPEI (March 13): Taiwan's vice president-elect and former de facto ambassador to Washington, Hsiao Bi-khim, is in the US this week for a private visit, a senior Taiwanese official and a US spokesperson said on Tuesday, a trip China said it "firmly opposes".

China claims democratically governed Taiwan as its own territory, despite Taiwanese objections, and has been angered by past visits to the US by Taiwan's president and vice president.

Chinese embassy spokesperson Liu Pengyu said China "firmly opposes" any form of official interaction between the US and "the Taiwan region", and referred to Hsiao Bi-khim as "a diehard 'Taiwan independence' separatist'".

"We firmly oppose any visit by Hsiao Bi-khim to the US in any name or under whatever pretext," Liu said, adding that the US should "not arrange any form of contact between the US government officials and Hsiao Bi-khim."

A Taiwanese official, who requested anonymity due to the sensitivity of the matter, told Reuters Hsiao arrived in the US this week and will spend the next few days there on a low-profile "personal trip" that includes packing up her personal belongings. The official declined to elaborate.

A spokesperson for the US State Department also said Hsiao was travelling "in her personal capacity to tend to personal matters", and did not respond when asked if she would be meeting US officials.

"The United States has a longstanding precedent of transits by Taiwan officials and visits by candidates and Vice President-elect before they assume office," the spokesperson said.

Hsiao was Taipei's de facto ambassador to the US from 2020 until last year, when she joined the Taiwanese presidential race decided in an election in January.

Hsiao, 52, is a fluent English speaker with deep connections in Washington. Diplomatic sources have told Reuters she can act as a key go-between for Taipei and Washington, which is the island's most important arms seller and international backer despite the absence of formal relations.