Two US carrier groups conducted joint operations in the South China Sea, the US Navy said on Tuesday, the first such exercise since July 2020 amid heightened tensions in the contested waters.

The Theodore Roosevelt Carrier Strike Group and the Nimitz Carrier Strike Group "conducted a multitude of exercises aimed at increasing interoperability between assets as well as command and control capabilities", the US Navy said.

The busy waterway is one of several flashpoints in testy Sino-US relations, with the United States continuing to challenge Beijing's territorial claims in the contested waters.