The United States often sends ships and aircraft into the South China Sea to "flex its muscles" and this is not good for peace, China's Foreign Ministry said on Monday, after a US aircraft carrier group sailed into the disputed waterway.

The strategic South China Sea, through which trillions of dollars in trade flows each year, has long been a focus of contention between Beijing and Washington, with China particularly angered by US military activity there.

The US carrier group led by the USS Theodore Roosevelt and accompanied by three warships, entered the waterway on Saturday to promote "freedom of the seas", the US military said, just days after Joe Biden...