A US aircraft carrier group sailed into the South China Sea on a so-called “freedom of navigation” exercise, the first routine operation in the region under new President Joe Biden. Led by the USS Theodore Roosevelt, the carrier strike group entered the area Saturday, the US Indo-Pacific Command said, the same day Taiwan reported multiple Chinese jets and bombers had flown into its air defense zone.

Beijing lays claims to nearly all of the South China Sea — despite Taiwan, the Philippines, Brunei, Malaysia and Vietnam also saying parts belong to them. China’s foreign ministry spokesman called the routine US exercises a “show of force and not conducive to the peace and stability of the region”. The South China Sea is a strategic waterway and also believed to have valuable oil and gas deposits.

The US operation comes days after Washington said its commitment to Taiwan is “rock-solid”, the first comments from the Biden administration on the democratic island.