China said on Monday it was extending threatening military exercises surrounding Taiwan that have disrupted shipping and air traffic and substantially raised concerns about the potential for conflict in the region.
The exercises would include anti-submarine drills, apparently targeting US support for Taiwan in the event of a potential Chinese invasion, according to social media posts from the eastern leadership of China's ruling Communist Party's military arm, the People's Liberation Army.
The military has said the exercises involving missile strikes, warplanes and ship movements crossing the midline of the Taiwan Strait dividing the sides were a response to US House Speaker Nancy Pelosi's visit to the self-ruled island last week.
China has ignored calls to calm the tensions, and there was no immediate indication when it would end what amounts to a blockade.
Taiwan's defence ministry said on Sunday it detected a total of 66 aircraft and 14 warships conducting the naval and air exercises.
The island has responded by putting its military on alert and deploying ships, planes and other assets to monitor Chinese aircraft, ships and drones that are "simulating attacks on the island of Taiwan and our ships at sea".
Meanwhile, Taiwan's official Central News Agency reported that Taiwan's army will conduct live-fire artillery drills in southern Pingtung County on Tuesday and Thursday, in response to the Chinese exercises.
The drills will include snipers, combat vehicles, armored vehicles as well as attack helicopters, said the report, which cited an anonymous source.
China claims Taiwan as its own territory and has threatened to annex it by force if necessary. The two sides split in 1949 after a civil war, but Beijing considers visits to Taiwan by foreign officials as recognizing its sovereignty.
Taiwan President Tsai Ing-wen has called on the international community to "support democratic Taiwan" and "halt any escalation of the regional security situation." The Group of Seven industrialised nations has also criticised China's actions, prompting Beijing to cancel a meeting between Foreign Minister Wang Yi and his Japanese counterpart, Yoshimasa Hayashi.
China has cut off defence and climate talks with the US and imposed sanctions on Ms Pelosi in retaliation for her visit.
The Biden administration and Pelosi say the US remains committed to the "one-China" policy that extends formal diplomatic recognition to Beijing while allowing robust informal relations and defence ties with Taipei.
The US however criticised Beijing's actions in the Taiwan Strait, with White House press secretary Karine Jean-Pierre calling them "fundamentally irresponsible".
On a visit to Myanmar, whose Chinese-backed military government has been accused of murdering its opponents, Chinese Foreign Minister Wang Yi said Washington was "taking the opportunity to build up its military deployment in the region, which deserves high vigilance and resolute boycott from all sides".
Meanwhile, Australian Foreign Minister Penny Wong called for a cooling of tensions. "Australia continues to urge restraint, Australia continues to urge de-escalation, and this is not something that solely Australia is calling for, and the whole region is concerned about the current situation, the whole region is calling for stability to be restored," she said.