China's Communist Party faces "severe challenges" including corruption and alienation from the people, Vice President Xi Jinping said Thursday after being appointed head of the ruling party.

"The party faces many severe challenges, and there are also many pressing problems within the party that need to be resolved, particularly corruption, being divorced from the people, going through formalities and bureaucratism caused by some party officials," Xi said.

"We must make every effort to solve these problems. The whole party must stay on full alert," he added, speaking on a stage in Beijing's Great Hall of the People before hundreds of Chinese and foreign journalists.

Appearing relaxed and confident, Xi spoke for about 19 minutes after taking the leadership of the world's most populous country and second-largest economy.

Xi, who succeeded Hu Jintao as general-secretary of the all-powerful party, is also expected to replace him as state president next March.

He will head a reshuffled and streamlined steering committee for the party of seven members, down from nine before.

Xi will govern for the next decade amid growing public anger over corruption and frequent reports of abuse of power by officials.

The party also stresses the need to reduce the economy's reliance on exports and investment and focus more on private enterprise and consumer demand.

Xi, standing on stage with the six other members of the Politburo Standing Committee and wearing a red tie, took the opportunity to thank the party. His speech was broadcast live on state television.

"On behalf of the members of the newly elected central leadership, I wish to express our heartfelt thanks to all other members of the party for the great trust they have placed in us," Xi said.

"We will strive to be worthy of their trust and fulfil our mission."

Xi also touched on improving the livelihood of the Chinese people.

"They wish to have better education, more stable jobs, more income, greater social security, better medical and health care, improved housing conditions and a better environment," he said.

"They want their children to have sound growth, have good jobs and lead a more enjoyable life. To meet their desire for a happy life is our mission."

The highly choreographed appearance began at 11:54 am (0354 GMT) with the members of the standing committee filing into a room in the hall in order of rank led by Xi, who waved as he entered.

He took no questions after his speech.