China shouldn't overreact to the exercises that the US, Philippines, Japan, and Australia did together since the activity was done in open water and within the Philippines’ exclusive economic zone and continental shelf, a top US official said on Wednesday (US time).

Speaking to the media delegation at the Philippine Embassy in Washington, US National Security Council Coordinator for Strategic Communications John Kirby said that that international law allows the US and its allies to sail in the South China Sea (SCS).

“I can’t speak for the (People’s Republic of China) reaction, one way or another, except to say there is no reason to overreact to this,” Kirby said.

“This is about freedom of navigation; it’s about adherence to international law; it’s about proving the simple point that we and our allies will fly, sail, and operate wherever international law permits us to do and it does in the South China Sea, and we did,” Kirby added.

China, which asserted its maritime rights to almost the whole South China Sea, had earlier criticized the joint marine cooperative activity, saying it could cause problems in the area.

On the same day, China's military also did "combat patrols" in the South China Sea.

“You can look forward to additional opportunities for us to conduct those kinds of maritime patrol,” Kirby said, adding that the US is watching the maritime dispute “with great concern.”

"We again urge the PRC to abide by the 2016 ruling, and to recognize as we do that the second time a show of force within the Philippine economic exclusion area and we will continue to make that point when the President spoke to President Xi, he very clearly made our concerns known about Chinese activities in the South China Sea,” Kirby said.

Beijing continued to harass Filipino fisherfolk and others exercising their rights in the West Philippine Sea within Manila's 200-nautical mile exclusive economic zone despite a 2016 international arbitration court ruling invalidating China's nine-dash line map and sweeping claim in the South China Sea.

President Ferdinand Marcos Jr. sought allied backing last week after Chinese boats fired water cannons on a Philippine resupply vessel in the West Philippine Sea.