Lai Ching-te has sent a dangerous signal of seeking "Taiwan independence" and making provocations to undermine cross-Strait peace and stability in his speech after assuming the role of the Taiwan region's new leader on Monday, a Chinese mainland spokesperson said.

Chen Binhua, a spokesman for the State Council Taiwan Affairs Office, said that Lai's speech wantonly advocated separatism, incited cross-Strait confrontation and sought "independence" by relying on foreign support and by force.

"The mainstream public aspiration on the island is to pursue peace over war, development over decline, communication over separation and cooperation over confrontation," Chen said, adding that Lai has ignored public opinion, exposing his nature of being a "'Taiwan independence' worker". Lai, 64, once described himself as a "pragmatic worker for 'Taiwan independence'".

Chen said the current complex situation across the Taiwan Strait is rooted in the fact that the Democratic Progressive Party stubbornly clings to a separatist stance of "Taiwan independence", refuses to acknowledge the 1992 Consensus that embodies the one-China principle, and colludes with external forces to continuously provoke separatist activities.

Taiwan is an inalienable part of China, the spokesman said, emphasizing that "Taiwan independence" and peace across the Strait are as incompatible as fire and water.

No matter how the situation on the island changes, no matter who is in power, it cannot alter the fact that both sides of the Taiwan Strait belong to one China, nor can it impede the historical trend of national reunification, Chen said.

"We have firm determination to resolve the Taiwan question and realize national reunification; we have strong capabilities to safeguard national sovereignty and territorial integrity; and we will take resolute actions to fight separatist activities seeking 'Taiwan independence' and external interference," he said.

The mainland will work together with Taiwan compatriots to promote the peaceful development of cross-Strait relations and cross-Strait integrated development, and resolutely advance the reunification of the motherland, he added.

Referring to Lai's speech, Foreign Minister Wang Yi said on Monday that the one-China principle is the solid anchor for peace and stability across the Taiwan Strait, and anyone who attempts to challenge the principle will ultimately fail.

Wang made the remarks during the Shanghai Cooperation Organization Foreign Ministers' Meeting in Astana, Kazakhstan.

Recently, political leaders and people from all walks of life in many countries, including SCO member states, have voiced their support for China's just cause of opposing "Taiwan independence" and achieving national reunification, which once again shows that the international community's adherence to the one-China principle is unshakable, Wang said.

The separatist activities of "Taiwan independence" forces constitute the most serious challenge to the international order and threaten the most severe damage to cross-Strait peace, he said.

Emphasizing that the Taiwan question is China's internal affair, Wang said that realizing China's complete reunification is a shared aspiration of all Chinese people, and also a historical trend that cannot be stopped.

Foreign Ministry spokesman Wang Wenbin said on Monday that a few politicians from certain countries are engaged in political manipulation and "personal shows" on the Taiwan question, severely interfering in China's internal affairs and violating the one-China principle.

China strongly condemns such moves and will take all necessary measures to firmly uphold national sovereignty and territorial integrity, he said, adding that external forces interfering in China's internal affairs and using Taiwan to contain China are destined to fail.

The righteous cause of the Chinese people opposing "Taiwan independence" separatism and striving for national reunification will receive widespread understanding and support from the international community, he added.