"(Lai's) provocations in seeking 'independence' are the root cause of trouble for peace and stability in the Taiwan Strait and will bring disaster to the people of Taiwan," said Chen Binhua, a spokesman for China's Taiwan Affairs Office.

China has not ruled out using force to bring the democratic island under its control, which Lai and his government oppose.

Lai pledged in his speech to defend the island's "national sovereignty".

But he also said Taipei's efforts to preserve the "status quo of peace and stability in the Taiwan Strait remain unchanged".

Beijing has ramped up pressure on Taiwan to accept its territorial claims and relations have remained tense under Lai, who took office in May.

China's foreign ministry spokeswoman Mao Ning told a regular news briefing earlier on Thursday that Lai's speech "exposed his hell bent position on Taiwan independence and his sinister intention to escalate tensions in the Taiwan Strait for political self-interest".

"Taiwan has never been a country and can never become one, so it does not have any so-called 'sovereignty'," Mao said.

She said Lai's comments "arbitrarily severed the historical connection between the two sides of the Taiwan Strait" and used "all manner of tactics to peddle the fantasy of Taiwan independence".

China maintains a near-daily military presence around Taiwan and has held three rounds of large-scale war games in the past two years, deploying aircraft and ships to encircle the island.

A senior US administration official said that China may use the National Day celebrations "as a pretext" for military exercises.

Beijing insisted following Lai's speech that "Taiwan is an inalienable part of Chinese territory" and that unification between the island and the mainland was "inevitable".