(Bloomberg) --

A U.K. frigate sailed through the Taiwan Strait, the first such passage by a British naval vessel since late 2019, as a group of nations led by Washington pushes back at Beijing’s military assertiveness.

The HMS Richmond transited the narrow body of water separating China from Taiwan on Monday on its way to Vietnam, according to the vessel’s Twitter account. Taiwan’s military is monitoring the area and is on top of the situation there, according to the island’s Ministry of National Defense.

The move by London comes as China has been ratcheting up military, economic and diplomatic pressure on Taipei and President Tsai Ing-wen, who refuses to endorse the claim that democratically run Taiwan is part of China. The Chinese air force has made more than 500 incursions into Taiwan’s air-defense identification zone so far in 2021, Defense Minister Chiu Kuo-cheng told lawmakers on Monday, compared with more than 300 a year in the past.

Earlier this month, Tony Radakin, an admiral in Britain’s navy, told Nikkei Asia that it was “very clear that the Taiwan Strait is international waters.” “It is a waterway that can be used by different nations,” he added. 

The Richmond, a frigate, is part of a strike group led by the HMS Queen Elizabeth aircraft carrier, which is making a maiden operational mission to the Pacific region. The last British ship to transit the Taiwan Strait in 2019 was a survey vessel. 

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The U.S. routinely sends warships through the Taiwan Strait, with nine passages so far this year, according to Bloomberg-compiled data, roughly on pace to match last year’s 13. The U.S Navy last transited on Sept. 17, a move it said illustrated “the U.S. commitment to a free and open Indo-Pacific.”

Australia, France and Canada have also sent naval vessels through the strait since late 2018.

On Friday, President Joe Biden met the leaders of Australia, India and Japan at the White House in their first-ever summit to discuss initiatives to counter Beijing’s influence in the Indo-Pacific. A joint statement mentioned the creation of a “Quad infrastructure partnership,” and that the four nations would meet regularly.

China claims Taiwan as part of its territory and has repeatedly threatened to take control of the island by military force if necessary to prevent Taipei from making a move toward formal independence. 

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