For the first time ever a US Navy aircraft carrier with F-35 stealth fighters on board has entered the South China Sea this week. The Carl Vinson Carrier Strike Group entered the contested waters near China days ago, and subsequently the Navy released a photo of an F-35 launching from the Carl Vinson.

This comes as the Arleigh Burke-class guided-missile destroyer USS Benfold is gaining most attention from Beijing after it sailed near Mischief Reef in the Spratly Islands, which is an area long claimed by China.

A subsequent report in Chinese state mouthpiece Global Times indicated that the presence of both the Benfold and stealth jet carrying Vinson carrier has put the PLA military on ‘high alert’.

Global Times wrote: “As the first carrier to get the F-35C, the USS Carl Vinson went straight to the South China Sea with the aim of deterring China, but China has already developed a number of anti-stealth radar systems, so the F-35C can be detected, Fu said, noting that China also has countermeasures against the vertical take-off and landing-capable CMV-22Bs, which could land on islands and reefs in the region.”

The PLA Southern Theater Command meanwhile charged the US Navy with “trespassing” and “violating” Chinese sovereign waters. It particular it claimed to have “warned off” the USS Benfold destroyer from near the reefs during the Wednesday incident. The US responded that the navy continues upholding lawful freedom of navigation operations.

State media also called the carrier’s arrival with the stealth jets on board a “provocative deployment” which China is able to counter if needed.