BEIJING, Oct 16 (AFP) - Chinese President Xi Jinping on Sunday (Oct 16) touted the fight against COVID-19 while calling for the acceleration of building a world class military as he opened the twice-a-decade Communist Party Congress by largely reiterating key policy priorities.

In a speech lasting less than two hours - far shorter than his nearly three-and-a-half-hour address at the last congress in 2017, Xi restated support for the private sector and allowing markets to play a key role, even as China fine-tunes a "socialist economic system" and promotes "common prosperity".

The biggest applause came when he restated opposition to Taiwan independence.

Xi is widely expected to win a third leadership term at the conclusion of the week-long congress, cementing his place as the country's most powerful ruler since Mao Zedong.

The gathering of roughly 2,300 delegates from around the country began in the vast Great Hall of the People on the west side of Tiananmen Square amid tight security and under blue skies after several smoggy days in the Chinese capital.

In recent days, Beijing has repeatedly emphasised its commitment to Xi's zero-COVID strategy, dashing hopes among countless Chinese citizens as well as investors that Beijing might begin exiting anytime soon a policy that has caused widespread frustration and economic damage.

Xi said little about COVID other than to reiterate the validity of a policy that has made China a global outlier as much of the world tries to coexist with the coronavirus.

"We have adhered to the supremacy of the people and the supremacy of life, adhered to dynamic zero-COVID ... and achieved major positive results in the overall prevention and control of the epidemic, and economic and social development," Xi said.

He described China as putting "the people and their lives first" and winning international praise when it came to dealing with the pandemic.

On Taiwan, Xi said, "We have resolutely waged a major struggle against separatism and interference, demonstrating our strong determination and ability to safeguard state sovereignty and territorial integrity and oppose Taiwan independence."

The delegates, wearing blue face masks, responded with loud and prolonged applause.

Xi said it was up to the Chinese people alone to resolve the Taiwan issue and that China would never renounce the right to use force.

"We will adhere to striving for the prospect of a peaceful reunification with the greatest sincerity and greatest efforts, but will never commit to abandoning the use of force, and reserve the option to take all necessary measures," Xi said.

That option is aimed at "interference" by external forces and a "very small number" of Taiwan independence supporters rather than the vast majority of the Taiwanese people, he said, adding that China has always "respected, cared for and benefited" Taiwan's people.

China views democratically ruled Taiwan as its own territory, despite the strong objections of the government in Taipei, which rejects the sovereignty claims and says only the island's people have the right to decide their future.

Tensions rose dramatically in August after China staged war games near Taiwan following the visit to Taipei of United States House Speaker Nancy Pelosi. Those military activities have continued though at a reduced pace.