Taiwan and China both applied in 2021 to join the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP), but China says it opposes Taiwan - which it claims as its own territory - joining.

Britain, seeking post-Brexit opportunities, has also applied to join the pact which removes 95% of tariffs between its 11 members - Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore and Vietnam.

Speaking to a group of visiting British lawmakers, Tsai said she hoped that Britain's accession to the CPTPP proceeded smoothly.

"I also hope that given its disposition for maintaining high standards, Britain will support Taiwan's bid to join the agreement. This would do much to allow Taiwan and Britain to continue deepening their partnership," she said.

In a statement released after a meeting in Singapore last October, trade pact members said Britain's application was progressing, and subsequent applicants would need to show "a demonstrated pattern of complying with their trade commitments".

Ecuador and Costa Rica have also applied to join.

China's embassy in Britain on Sunday condemned the visit of the British lawmakers to Taiwan, saying they were insisting on visiting the island despite China's strong opposition.

Britain, like most countries, has no formal diplomatic ties with Taiwan, but has been keen to show its support in the face of China's threats.

China has been ramping up military, political and economic pressure against Taiwan to assert its sovereignty claims.

Taiwan regularly hosts visiting foreign lawmakers, especially from fellow democracies, which China routinely condemns.

Taiwan's government rejects China's sovereignty claims, saying only Taiwan's people can decide their future.