China's military has criticised the sailing of a British warship through the Taiwan Strait as a deliberate attempt to "cause trouble", as Taiwan's president ordered stepped-up monitoring in response to Chinese military activities.

China, which views Taiwan as its own territory, though Taipei rejects that claim, has stepped up drills around the island over the past five years, including staging war games that have alarmed Taiwan, Washington and Tokyo.

Britain's Royal Navy said the patrol vessel HMS Spey conducted a routine navigation through the narrow waterway that was part of a long-planned deployment and took place in full compliance with international law.

China considers the strait to be Chinese waters, although Taiwan, the United States and many of its allies say it is an international waterway.

The Eastern Theatre Command of China's People's Liberation Army said the Wednesday sailing of the ship was "public hyping" and that its forces followed and monitored the Spey.

"The British side's remarks distort legal principles and mislead the public; its actions deliberately cause trouble and disrupt things, undermining peace and stability in the Taiwan Strait," it said.

"Troops in the theatre are on high alert at all times and will resolutely counter all threats and provocations."

Taiwan's government welcomed the sailing.

"The foreign ministry welcomes and affirms the British side once again taking concrete actions to defend the freedom of navigation in the Taiwan Strait, demonstrating its firm position that the Taiwan Strait is international waters," the ministry said.

China has over the past five years stepped up its drills around Taiwan, including staging war games that have alarmed Taipei, Washington and Tokyo.

Taiwan President Lai Ching-te earlier ordered defence and security units to step up their monitoring and intelligence efforts in response to China's military activities, which he said have not abated even as tensions rise in the Middle East.

In Beijing, foreign ministry spokesperson Guo Jiakun said Taiwan's ruling Democratic Progressive Party (DPP) was trying to "latch onto a hot topic".

"No matter what they say or do, it cannot change the fact that Taiwan is a part of China," he added.

Taiwan's defence ministry reported another spike over the previous 24 hours in Chinese movements close to the island, involving 50 aircraft, concentrated in the strait and the top part of the South China Sea.

The last time a British warship sailed through the strait was in 2021, when HMS Richmond was deployed in the East China Sea en route to Vietnam. Chinese military followed it at the time and warned it away.

The latest passage comes at a time when Britain and China are seeking to mend their relations, with Prime Minister Keir Starmer expected to visit Beijing later this year - the first trip to the country by a British leader since 2018.

US Navy ships sail through the strait around once every two months, sometimes accompanied by allied nations.