Warship HMS Richmond has sailed through the Taiwan Strait – prompting China to accuse Britain of engaging in behaviour that "harbours evil intentions".
In a post on Twitter, People's Daily, China, the state-affiliated media outlet, said the British frigate was "tracked and monitored" as it sailed through the waterway.
The frigate, currently on the Carrier Strike Group 21 (CSG21) deployment, sailed through the waterway as it travelled to Vietnam.
The China state-affiliated media outlet said "with ill intentions, UK's move destroyed peace and stability in the area".
And the People's Liberation Army's Eastern Theatre Command said the "behaviour harbours evil intentions and damages peace and stability in the Taiwan Strait".
"Theatre command forces always maintain a high level of alert and resolutely counter all threats and provocations," it said.
A Ministry of Defence (MOD) spokesperson said "wherever the Royal Navy operate, they do so in full compliance with international law".
"The UK has a range of enduring security interests in the Indo-Pacific and many important bilateral defence relationships. This deployment is a sign of our commitment to regional security," the MOD spokesperson said.
The last British frigate or destroyer to travel through the Taiwan Strait was HMS Kent in 2008, and survey vessel HMS Enterprise navigated the strait in 2019.
US warships sail through the waterway on a more frequent basis, despite opposition from China, but US allies have generally been hesitant to do so.
However, in a recent Defence Select Committee evidence session, Tetsuo Kotani, a senior fellow at the Japan Institute of International Affairs, said he expected one ship from the Carrier Strike Group to sail through the Taiwan Strait.
"Otherwise, China will be emboldened," he said.
Beijing claims Taiwan as part of its territory, despite the democratically elected Taiwanese government's refusal to do so.
Earlier this year, China held naval drills near Taiwan, stating the exercises aimed to "assist in improving the ability to safeguard national sovereignty, security and development interests".