Xi Jinping was re-elected to a second five-year term as China's president by the National People's Congress on Saturday and his confidant Wang Qishan became vice president, with fears growing about the return of long-term dictatorship in the Asian power.

Wang, who has held several key posts in the ruling Communist Party of China and the government, will support the president, as Xi is believed to be eager to dominate the country's politics for the next decade and beyond.

Earlier this month, the National People's Congress, China's parliament, agreed to remove from the nation's Constitution the two-term limit for the president and vice president, effectively paving the way for Xi to remain in office indefinitely.

China's congress unanimously approved Xi's re-election. One legislator voted against Wang's appointment as vice president, with 2,969 in favor.

After being elected, Wang walked up to Xi with a smile and shook hands with him. The hall of the parliament erupted with applause and shouts.

Xi and Wang took the oath of office by pledging allegiance to the Constitution, into which the president's political thought was incorporated as the amendment of the country's supreme law was enacted for the first time since 2004 earlier this month.

Enshrined in the Constitution is Xi's goal of making China a "great modern socialist country" by the middle of the 21st century.

The term limits were instituted in 1982 by former leader Deng Xiaoping, as he wanted to prevent a return to the 10-year chaos of the Cultural Revolution, initiated in 1966 by Mao Zedong who remained in power until his death in 1976.

The current version of China's Constitution, enacted in 1982, had been revised four times, mostly to advance the policy of "reform and opening-up" advocated by Deng, with the goal apparently of embracing Western values.

But the latest constitutional revision emphasizes the unquestioned authority of Xi, with some analysts warning that China has turned back the clock and its long-established collective leadership system will be turned into a mere formality.

Wang has played a pivotal role in leading Xi's extensive anti-corruption drive since 2013. He was replaced in October as head of the Central Commission for Discipline Inspection in line with the party's informal retirement age.

It is rare for a person retired from the party's apex of power to be appointed as vice president.

Wang, who was one of the seven members of the Politburo Standing Committee, served as vice premier in charge of financial affairs and worked on economic negotiations with the United States.

Xi is expected to ask Wang to deal with the recent trade disputes with Washington, which decided to impose tariffs on steel and aluminum imports, escalating tensions with China and other trading partners.

The National People's Congress, meanwhile, appointed Li Zhanshu, the third-highest ranking official in the ruling party, as the head of parliament on Saturday.

An institutional reform plan, including proposals to establish new ministries aimed at promoting environmental protection, was also approved, as Xi has promised to build a "Beautiful China" with blue skies and clean air.

It is the first large-scale institutional reform by the Chinese government in five years.