China's president renewed his promise to achieve what he calls the "reunification of Taiwan" as the Communist Party's National Congress kicked off in Beijing. The twice-in-a-decade meeting is expected to cement the authority of Xi Jinping.

More than 2,000 delegates from across China are gathering for the meeting. They will decide on key policies over the next seven days.

Xi pledged his party would push to reunify Taiwan by using force if necessary.

He said, "We will continue to strive for peaceful reunification with the greatest sincerity and the utmost effort, but we will not promise to renounce the use of force, and we reserve the option to take all necessary measures."

Xi praised what he calls the party's historic achievements over the past five years, including the eradication of severe poverty.

He also boasted about China's hardline coronavirus measures. Critics say his "zero-COVID" strategy has slowed the country's economy and caused deep frustration among average people.

Xi said, "We put all of our power into the battle against the pandemic for the Chinese people. We have protected people's health and safety to the greatest extent possible, and we have seen tremendously encouraging achievements with our anti-virus measures and our economic and social development."

The party will amend its constitution at the congress. It is expected to add political slogans to cement Xi's "core position" in the party and demand absolute loyalty.

And delegates will set the stage for an unprecedented third term for Xi. That would break an unwritten rule. Members of the top leadership positions are supposed to step down at the age of 68. Xi turned 69 this year.