The exercises in the Taiwan Strait and around groups of Taiwan-controlled islands beside the Chinese coast come just three days after Lai took office.
China, which views democratically governed Taiwan as its own territory and denounces Lai as a "separatist", decried his inauguration speech on Monday, in which he urged Beijing to stop its threats and said the two sides of the strait were "not subordinate to each other".
On Tuesday, Chinese Foreign Minister Wang Yi called Lai "disgraceful".
Lai has repeatedly offered talks with China but has been rebuffed. He says only Taiwan's people can decide their future, and rejects Beijing's sovereignty claims.
The Eastern Theatre Command of the Chinese People's Liberation Army (PLA) said it had started joint military drills, involving the army, navy, air force and rocket force, in areas around Taiwan at 7:45 a.m. (2345 GMT).
The drills are being held in the Taiwan Strait, the north, south and east of Taiwan, as well as areas around the Taiwan-controlled islands of Kinmen, Matsu, Wuqiu and Dongyin, the command said in a statement, the first time China's exercises have included areas round these islands.
State media said China sent out dozens of fighter jets carrying live missiles, and conducted mock strikes, along with warships, of high-value military targets.
Taiwan's defence ministry said 15 Chinese navy ships, 16 coast guard and 33 aircraft were involved, but no live fire drills were held in any areas close to Taiwan.
The drills, dubbed "Joint Sword - 2024A", are set to run for two days. However, unlike a similar "Joint Sword" exercise in April last year, these drills are tagged "A", opening the door to potential follow-ups.
Taiwan's defence ministry said it had sent forces to areas around the island, with its air defences and land-based missile forces tracking targets. It said it was confident it could protect its territory.
"The launch of military exercises on this occasion not only does not contribute to the peace and stability of the Taiwan Strait, it also highlights (China's) militaristic mentality," the ministry said.
The U.S. State and Defense departments put out identical statements strongly urging Beijing to act with restraint and saying it should not use Taiwan's political transition as a "pretext or excuse for provocative or coercive measures."
"(China's) actions risk escalation and erode longstanding norms that have maintained regional peace and stability for decades," they said.
Analysts, regional diplomats and senior Taiwan officials noted that so far the operations around Taiwan are smaller than the those China staged to protest at the August 2022 visit to Taipei of then-U.S. House Speaker Nancy Pelosi.
Then China staged live-fire drills as part of exercises that ran for days and were denounced by the U.S. as "extreme, disproportionate and escalatory."
Taiwan's presidential office expressed regret that China was threatening the island's democratic freedoms and regional peace and stability with its "unilateral military provocations", but said Taiwan could ensure its security.
"I have confidence in the military," Lai said at a military base in Taoyuan, near Taipei. "I also ask all my compatriots to rest assured."
China's state broadcaster CCTV said Lai's inauguration speech was "extremely harmful" and China's countermeasures "legitimate, legal and necessary".
It said Lai's speech was a confession of a desire for Taiwan independence and undermined peace and stability across the strait. Taiwan's future can only be decided by China's 1.4 billion people, not just Taiwan's 23 million people, it added.
Over the past four years, China's military has carried out almost daily activities near Taiwan, and last staged large-scale war games near the island in 2023 and 2022.
One senior Taiwan official, who sought anonymity as the matter is sensitive, said this time around China was essentially "putting a name" on its regular activities, rather than a dramatic escalation.
Those drills include crossing the strait's median line, which had previously served as an unofficial barrier, and staging mock attacks on Taiwanese and foreign vessels, the official added.
No Suprise
Another senior Taiwan official told Reuters the drills were part of a scenario Taiwan had anticipated.
China's military said the drills focused on joint sea-air combat-readiness patrols, precision strikes on key targets, and integrated operations inside and outside the island chain to test the "joint real combat capabilities" of the forces.
"This is also a strong punishment for the separatist acts of Taiwan independence forces and a stern warning against the interference and provocation by external forces," the command added.
Chinese state media published a map of the drill zones, in five areas all around Taiwan and the islands Taiwan controls near the Chinese coast.
Taiwan officials told Reuters those areas were outside Taiwan's contiguous zone, which is 24 nautical miles from the main island's coast.
One of the officials said China had not announced any no-fly zones, nor had Taiwan observed any large-scale movements of China's ground and rocket forces.
Su Tzu-yun, a research fellow at Taiwan's top military think tank, the Institute for National Defence and Security Research, said that although the drills would only last two days, their scope was large relative to previous exercises, as they included Taiwan's outlying islands.
This is designed to demonstrate China's ability to control the seas and prevent the involvement of foreign forces, he said.
"The political signals here are greater than the military ones," he added.
REUTERS
