The drills come after Lai Ching-te was sworn in as Taiwan's new president this week and made an inauguration speech that China denounced as a "confession of independence".

Communist China claims Taiwan as part of its territory and has vowed to bring the island under its rule, by force if necessary.

Thursday and Friday's drills involve military aircraft and naval vessels surrounding the island.

This will "test the joint real combat capabilities of the forces of the command", the Chinese military said.

Taiwan responded quickly to China's announcement on Thursday morning, announcing it had deployed forces to "defend freedom".

"The Ministry of National Defence strongly condemned such irrational provocations and actions that undermine regional peace and stability.

"We have dispatched sea, air and ground forces to respond... to defend freedom, democracy and the sovereignty of the Republic of China," it said, referring to Taiwan by its official name.

On Tuesday, China warned of strong reprisals to Lai's speech, in which he hailed a "glorious" new era of democracy for Taiwan.

Top diplomat Wang Yi also warned that Taiwanese "separatists will be nailed to the pillar of shame in history".

China had previously branded Lai a "dangerous separatist" who would bring "war and decline" to the island.

- 'Joint Sword-2024A' -

China's drills will "focus on joint sea-air combat-readiness patrol, joint seizure of comprehensive battlefield control, and joint precision strikes on key targets", spokesman for the People's Liberation Army's Eastern Theater Command Naval Colonel Li Xi said.

They are taking place in the Taiwan Strait and to the north, south and east of the island and kicked off at 7:45 am (2345 GMT), Li said.

This week's drills will also take place around the outlying islands of Kinmen, Matsu, Wuqiu and Dongyin, he added.

"Ships and aircraft arrived at combat patrols near Taiwan Island... to test the actual joint combat capabilities of the theatre forces," Li said.

The drills would also serve as a "strong punishment for the separatist acts of 'Taiwan independence' forces and a stern warning against the interference and provocation by external forces", he said.

Beijing, which split with Taipei at the end of a civil war in 1949, regards the island as a renegade province with which it must eventually be reunified and has refused to rule out using military force to do so.

Relations have plunged in recent years as China has stepped up pressure on the democratic island, periodically stoking worries about a potential invasion.

- 'Real combat conditions' -

Beijing "clearly feels it needs to send a very strong message to Lai and anyone who supports him", analyst Bill Bishop wrote in his influential Sinocism newsletter.

"I would be surprised if this new exercise is smaller and less threatening than any last year," he said.

The last time China announced similar military exercises around Taiwan was in August 2023 after Lai, then vice president, stopped over in the United States on a visit to Paraguay.

Those drills also tested the PLA's ability "to seize control of air and sea spaces" and fight "in real combat conditions", according to state media.

Beijing at the time described them as a "stern warning".

They followed on the heels of April drills that simulated the encirclement of the island, triggered after Lai's predecessor Tsai Ing-wen met then-US House Speaker Kevin McCarthy in California.

China also launched major military exercises in 2022 after Nancy Pelosi, then the speaker of the US House of Representatives, visited Taiwan.

The country also held drills when then-president Tsai later transited through the United States.

World powers are keen to see as much stability as possible between China and Taiwan, not least because of the vital role the island plays in the global economy.

The Taiwan Strait is one of the world's most important maritime trade arteries, and the island itself is a major tech manufacturer, particularly of vital semiconductors -- the tiny chips used in everything from smartphones to missile systems.