BEIJING, March 3 (Xinhua) -- China's top political advisory body started its annual session Saturday afternoon in Beijing, kicking off an important political season that will highlight new missions for the country's goal of a "great modern socialist country."

Yu Zhengsheng, chairman of the 12th Chinese People's Political Consultative Conference (CPPCC) National Committee, delivered a work report to 2,149 political advisors who gathered to discuss major political, economic, and social issues in the world's most populous nation and second largest economy.

"We will focus our advice and efforts on the main issues in securing a decisive victory in building a moderately prosperous society in all respects and embarking on a journey to fully build a modern socialist China," Yu said.

Xi Jinping and other Chinese leaders attended the opening meeting at the Great Hall of the People.

The CPPCC is an important organ for multiparty cooperation and political consultation led by the Communist Party of China (CPC). It is an important means of promoting socialist democracy.

Summarizing the work and experience over the past five years, Yu said the CPPCC should remain committed to its nature as "an important platform for all Chinese political parties, social organizations, and people from all ethnic groups and all sectors of society to work together and participate in the deliberation of state affairs in a democratic manner."

He stressed that the top political advisory body will uphold the CPC leadership.

In regards to its future work, the CPPCC will give top priority to studying and applying Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era, and earnestly study the new thinking on and requirements for the patriotic united front and the CPPCC, Yu said.

"We will promote the ready acceptance of the leadership of the CPC among all political parties, social groups, and people of all ethnic groups and from all social sectors that participate in the CPPCC, and firmly uphold the core position of General Secretary Xi Jinping," he noted.

The CPPCC will consolidate a shared political foundation for concerted efforts, sharpen political advisors' skills across the board, and improve the institutions, standards and procedures for the performance of its functions, he said.

In a report on proposals, Wan Gang, vice chairperson of the 12th CPPCC National Committee, said over the past five years, a total of 29,378 proposals had been submitted by the CPPCC National Committee members, and 99 percent of them had been handled up to Feb. 20 this year.

"Most of the proposals have either been taken up or put into practice gradually," Wan said.

The 13-day event runs almost in parallel with the annual session of the National People's Congress (NPC), China's national legislature, which is set to start Monday.

Together dubbed the "two sessions," the dual meetings are regular yet crucial venues where political and economic developments are reviewed and discussed, and key policies and laws adopted.

The more than 2,100 national political advisors and about 3,000 legislators are expected to offer proposals and insights for the government on running state affairs during this year's annual sessions.

The sessions are among the most important political events held since the 19th CPC National Congress in October, which charts the roadmap for China's development in the next decades.

This year's gatherings are expected to garner more attention both at home and abroad as they offer a window for global observers to look into China's next-stage policies.

On the agenda of this year's two sessions is a revision to China's Constitution, which is likely to enshrine Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era to guide future development.

A draft law on supervision is also set to be deliberated and discussed, which will lay a legal basis for an upgraded anti-graft taskforce in a major political system reform process.

A government work report to the NPC session will reveal the nation's economic growth target and development plan for this year.

China's economy expanded 6.9 percent last year, picking up for the first time in seven years and well above the official target of around 6.5 percent.

A report delivered by Xi at the 19th CPC National Congress declared the opening of a new era for socialism with Chinese characteristics.

The report offered two clear objectives: socialist modernization basically completed by 2035, and a "great modern socialist country" built by the middle of the century.

"In response to the need for development in the new era, we will put forward suggestions on how to develop a modern economy and socialist democracy, help culture to flourish, strengthen and develop new approaches to social governance, and build a Beautiful China," Yu stressed.