Chinese leader Hu Jintao pledged to make communist rule more inclusive and better spread the fruits of China's economic boom, in an address Monday to a party congress that offers a key test of his authority.

Hu also offered talks on a formal peace accord with Taiwan, but the vague proposal included preconditions previously unacceptable to the island, which quickly rejected it.

Shying away from the warlike rhetoric that often accompanies such occasions, Hu instead stressing Beijing's preference for a peaceful, negotiated settlement to the 58-year-old conflict with Taiwan.

"We would like to make a solemn appeal: On the basis of the one-China principle, let us discuss a formal end to the state of hostility between the two sides, reach a peace agreement," Hu told the party and military elite gathered in the Great Hall of the People in central Beijing.

Hu's speech is the most public event at the congress, which comes at the midway mark of his decade-long tenure as party chief and head of state.

The weeklong conclave's chief purpose is to reappoint Hu for a second five-year term as party general secretary. A key measure of Hu's influence will be how many of his political allies he can maneuver into top party jobs, including proteges expected to take over when he steps down in five years.

Hu's leadership has never been threatened, but he is largely seen as weaker than past leaders, forcing him to compromise on some top appointments and other decisions. In a sign of possible constraints, Hu's retired predecessor, Jiang Zemin, was appointed to the committee handling the congress' arrangements, state media said Sunday.

In his address, Hu outlined policies intended to make China more prosperous and stable by raising incomes and improving the party's hold on a fast-changing society.

While offering few specifics, Hu said Chinese citizens would have "more extensive democratic rights" by 2020, China's target year for establishing lasting economic security, even as the party retains its monopoly on political power.

"Contemporary China is going through a wide-ranging and deep-going transformation. This brings us unprecedented opportunities as well as unprecedented challenges," Hu told the more than 2,200 delegates gathered in Beijing's massive Great Hall of the People for the once-every-five-year meeting.

Broadcast live on nationwide television, the far-ranging speech lasting more than two hours and 20 minutes was one of Hu's most important public addresses since taking over as party leader at the last congress in 2002.

Reflecting Hu's cautious manner, it contained few initiatives and was vague on just how proposals for expanded democracy would be carried out.

Hu also promised to continue a buildup of China's military, but pledged to use the country's economic and diplomatic clout as a force for peace internationally.

"I think the secretary-general did very well with this speech," said Shen Ruixiang, a district party secretary from the thriving eastern province of Jiangsu.

"I'm sure he'll emerge from this congress with even more authority and prove an even better leader," Shen said.

Hu dwelled also on his signature policy, a push to re-channel breakneck development by spreading the benefits of economic growth more evenly that goes by the rubric "the scientific outlook on development."

Hu referred to the social divisions that have erupted from fast growth — gaps between rich and poor, urban and rural — and made an oblique reference to an emerging, demanding middle class.

"There are still a considerable number of impoverished and low-income people in both urban and rural areas, and it has become more difficult to accommodate the interests of all sides."

While Hu spoke, police and soldiers who sealed off Tiananmen Square and the areas around the Great Hall of the People detained at least two dozen people, many of them elderly, forcing them into police vans. Many carried documents detailing grievances against local officials and hoped to get the attention of Chinese leaders.

In looking outward, Hu reiterated an offer to end the hostilities between China and Taiwan since their separation amid civil war 58 years ago. Hu, however, restated a condition for talks that has been anathema to Taiwan's democratic government — that the island must recognize that it is a part of China.

Hu reveled in the achievements China has made since he took over, pointedly referring to income growth and its two manned space missions.

"During this period, China's overall strength grew considerably and the people enjoyed more tangible benefits. China's international standing and influence rose notably," Hu said.

Deliberations over the next leadership lineup have been going on for months and will take place this week behind closed doors. Its makeup is officially announced after the congress ends.

Hu is expected to push for the elevation of protege Li Keqiang onto the Politburo Standing Committee, while Xi Jinping, the party boss of Shanghai and the son of a revolutionary veteran, is also expected to get a seat.