The Eastern Theatre Command said Tuesday's drills would take place until 7pm AEDT in the sea and airspace of five locations surrounding the island, demonstrating the Chinese military's resolve to "combat separatism and promote unification without hesitation."
China's Maritime Safety Administration on Monday designated two further zones within which live-firing would take place, making the Justice Mission 2025 drills the largest to date by total coverage and in areas closer to Taiwan than previous exercises.
The war games began 11 days after the US announced a record $US11.1 billion arms package to Taiwan, drawing the Chinese defence ministry's ire and warnings that the military would "take forceful measures" in response.
The exercises - China's sixth major round of war games since 2022, when then-US House Speaker Nancy Pelosi visited the democratically governed island - are intended to rehearse a rapid encirclement of the island to destroy its weapons stockpile and obstruct efforts to resupply Taiwan from Japan or nearby US bases, analysts say.
"This constitutes a blatant provocation of the international situation," said a senior Taiwan security official, who requested anonymity due to the sensitivity of the matter.
"As one of the world's most critical shipping lanes, they seek to reshape the international order according to their own agenda."
The official said Taipei is closely monitoring whether China would seek "further provocation" in the drills on Tuesday, including flying missiles over Taiwan, similar to the Chinese drills in 2022.
"China is trying to make progress in asserting dominance over the entire island chain through extreme pressure tactics in various ways," the official said.
The Chinese military said it had deployed destroyers, bombers and other units to drill sea-based assaults, air defence and anti-submarine operations on Tuesday, to "test sea and air forces' ability to co-ordinate for integrated containment and control."
Taiwan rejects China's claimed sovereignty, maintaining that only its people can decide the island's future.
US President Donald Trump said he was not informed of the military exercises in advance but that he was not worried either, because China has been "doing naval exercises for 20 years in that area."
Touting his "great relationship" with Chinese President Xi Jinping, Trump suggested he didn't think Xi was going to attack Taiwan.
Beijing sends warplanes and navy vessels toward the island on a near-daily basis, and in recent years it has stepped up the scope and scale of the exercises.
