China's military on Friday condemned the sailing of a US and British warship through the sensitive Taiwan Strait, saying it ordered naval and air forces to monitor and warn the two ships.
The People's Liberation Army's Eastern Theater Command said the US destroyer USS Higgins and British frigate HMS Richmond were engaged in "trouble-making and provocation".
"The actions of the United States and Britain send the wrong signals and undermine peace and stability across the Taiwan Strait," it said in a statement.
The US and British militaries did not immediately respond to requests for comment.
Last week, a Canadian and an Australian warship also sailed through the strait.
The US Navy and, on occasion, ships from allied countries including Canada, Britain and France transit the strait, which they consider an international waterway, around once a month. Taiwan also considers it an international waterway.
China, which views Taiwan as its own territory, says the strategic waterway is part of its territorial waters. Taiwan's government rejects Beijing's territorial claims.
China has over the past five years increased its military pressure on the island, including by staging war games nearby.