China on Monday launched new military drills off the coast of Taiwan in what it described as "punishment" for a speech given by its president William Lai, when he vowed to "resist annexation" or "encroachment upon our sovereignty".
China claims the self-governing island of Taiwan as its own and its president Xi Jinping has vowed to retake it by force if necessary.
Taiwan said it detected 70 naval vessels, 125 aircraft and several Chinese coast guard vessels in formation around the island on Monday morning.
Maps published by Chinese state media indicated its forces were positioned around the whole island.
The Chinese military said the ongoing drills involved all wings of the People's Liberation Army, and were designed to simulate attacking Taiwan by land, sea and air.
In response, Taiwan's President William Lai said some of the island's forces had been deployed to monitor the situation and were "holding their positions".
Taiwan's airports and ports continued functioning as normal.
An earlier statement from the Taiwanese defence ministry condemned the Chinese move and said its priority was to avoid direct clashes which could escalate the stand-off further. Outlying islands were put on high alert, it added.
China's foreign ministry confirmed it had simulated military assaults and port blockades, and described Taiwanese independence as being "incompatible" with peace in the region.
China has held several major military drills off the coast of Taiwan since 2022 and its fighter jets regularly enter Taiwanese airspace.
The latest exercise has been dubbed Joint Sword 2024-B by Beijing and had been widely expected since May, when drills bearing the same name and officially labelled as part A were staged.
That exercise, which China described as its largest yet, were timed to coincide with the inauguration of President Lai, who Beijing has long seen as a "troublemaker" advocating for Taiwan's independence.
His latest comments, made on Taiwan's national day, were condemned by China, which said he was escalating tensions with "sinister intentions".