The three senators, Tammy Duckworth, Dan Sullivan and Christopher Coons, visited Taipei for around three hours on Sunday where they met President Tsai Ing-wen and announced the donation of 750,000 COVID-19 vaccine doses for the island

China's Defence Ministry expressed its strong opposition to the trip and use of the military aircraft

China's Defence Ministry on Tuesday denounced a brief weekend visit by three US senators to Chinese-claimed Taiwan on a US military aircraft as a "vile political provocation" that was irresponsible and dangerous.

The three senators, Tammy Duckworth, Dan Sullivan and Christopher Coons, visited Taipei for around three hours on Sunday where they met President Tsai Ing-wen and announced the donation of 750,000 Covid-19 vaccine doses for the island.

Unusually, they travelled on a US Air Force C-17 Globemaster-III freighter, rather than an unmarked private jet as is generally the case for senior US visitors.

China's Defence Ministry expressed its strong opposition to the trip and use of the military aircraft.

"The US senators visited Taiwan by military plane, using the Taiwan issue to engage in a 'political show', challenging the one-China principle and trying to achieve the so-called goal of 'using Taiwan to control China'", it said.

"This was an extremely vile political provocation".

Beijing says the democratically ruled island is part of "one China" and routinely denounces visits by foreign officials as an interference in the country's internal affairs.

The United States, like most countries, has no formal diplomatic ties with Taiwan but is its strongest international backer and main source of arms, to China's anger.

China believes Tsai is a separatist bent on declaring independence. She says Taiwan is already an independent country called the Republic of China, its official name.

The ministry said the trip damaged the basis of Sino-US ties and peace and stability in the Taiwan Strait, and was "extremely irresponsible and very dangerous".

The United States must immediately stop any kind of official exchanges or military relations with Taiwan, it added.

"If anyone dares to separate Taiwan from China, the Chinese People's Liberation Army will resolutely fight head-on at all costs and resolutely defend the country's unity and territorial integrity".