National reunification by peaceful means is the "first choice in resolving the Taiwan question", said a spokesman for the 20th National Congress of the Communist Party of China on Saturday.

"Peaceful reunification and 'one country, two systems' are our basic principles for resolving the Taiwan question," said Sun Yeli, the spokesman for the congress.

Sun stressed that promoting national reunification by peaceful means best serves the interests of the Chinese nation as a whole, including the compatriots in Taiwan, and works best for the long-term stability and development of China.

"We will continue to strive for peaceful reunification with utmost sincerity and utmost efforts, and will create vast space for peaceful reunification," he said.

Meanwhile, he underscored the significance of "not renouncing the use of force and reserving the option of taking all necessary measures".

"That is to guard against external interference, a small handful of 'Taiwan independence' elements and their separatist moves. By no means does this target our fellow Chinese in Taiwan," he said, adding that the ultimate goal is to strive for the prospect of peaceful reunification.

"As long as there is a slim chance for peaceful reunification, we will do our best," Sun said, noting that the use of force would be "the last resort under compelling circumstances".

He also outlined the current tensions across the Taiwan Straits and warned of "severe consequences" they could have.

"Currently, the 'Taiwan independence' forces keep making provocations, and external forces are doubling down on using Taiwan to contain China," he said. "These have severely undermined the fundamental interests of the Chinese nation and immediate interests of compatriots across the Taiwan Straits, and have severely jeopardized peace and stability across the Straits and threatened the prospect of peaceful reunification."

"If left unchecked, that will plunge Taiwan into an abyss and bring disaster to our compatriots," Sun warned, emphasizing that no one and no force should underestimate the "strong resolve, firm will and great capability" of China to defend national sovereignty and territorial integrity.

He hoped that Taiwan compatriots would be clear about the truth: "reunification has bright prospects; 'Taiwan independence' leads nowhere; and external forces are unreliable."