The US Navy said the guided-missile destroyer USS Sampson conducted a “routine Taiwan Strait transit” yesterday, in accordance with international law.

The US has been carrying out such sailings about once a month, angering China, which sees them as a sign of support for Taiwan, the democratically governed island that Beijing views as Chinese territory.

The People’s Liberation Army’s Eastern Theatre Command said its forces monitored and warned the ship.

“The United States frequently carries out such provocative actions, sending wrong signals to ‘Taiwan independence’ forces, and deliberately undermining the peace and stability of the Taiwan Strait. We firmly oppose it,” it said in a statement.

Taiwan’s defence ministry said the US ship sailed north through the strait, and that the situation in the waterway was “as normal”.

US 7th Fleet spokesperson Nicholas Lingo said in a statement that US military flies, sails, and operates anywhere international law allows.

“The ship’s transit through the Taiwan Strait demonstrates the United States’ commitment to a free and open Indo-Pacific,” Lingo said.

The US, like most countries, has no formal diplomatic ties with Taiwan but is its most important international supporter and arms supplier, making it a constant source of tension between Beijing and Washington.