HANOI (Reuters) - Vietnam’s parliament approved a new prime minister on Thursday, handing former bureaucrat and legislator Nguyen Xuan Phuc the challenge of maintaining the momentum of one of Asia’s fastest-growing economies.

Vietnam's Deputy Prime Minister Nguyen Xuan Phuc (R) chats with former Politburo member of To Huy Rua before the opening ceremony of the National Assembly's spring session in Hanoi, March 21, 2016. REUTERS/Kham

Phuc rises from deputy prime minister to lead a government committed to overhauling its troubled state sector and broad reforms under a U.S.-led Trans-Pacific Partnership, a major trade pact covering four-tenths of the global economy.

The 61-year-old completes the trio of core leaders of a youthful country hooked on social media, and growing in its awareness of politics and Vietnam’s complex ties with China and the United States.

Phuc has some big shoes to fill, taking over from Nguyen Tan Dung, a tough-talking reformist whose decisiveness won him broad support but, say experts, saw him sidelined by conservatives concerned he would become too powerful.

Vietnam is officially ruled by consensus with key decisions made by the Communist Party’s elite politburo.

Dung had served a maximum two terms and is no longer a politburo member, although key policy makers from his government are among the new 19-member body.

“Phuc certainly will be lower key than the hard-charging Dung,” said Murray Hiebert, a Southeast Asia specialist at Washington’s Center for Strategic and International Studies.

“We should expect him to operate within the consensus of the ruling politburo. He will have seen the impact on Dung of his more flamboyant, independent style.”

Phuc was the only candidate chosen at the party’s January congress. His appointment for a five-year term was approved by 475 of 480 lawmakers present.

He is from the central province of Quang Nam and his expertise is management and economics. He held key posts in local politics and on legislative committees and was once head of planning and investment in Danang, Vietnam’s third-biggest city.

Phuc becomes part of a new triumvirate with party chief Nguyen Phu Trong and President Tran Dai Quang, who was endorsed last week.

Addressing the assembly, Phuc pledged to achieve targets for the economy, which grew 6.7 percent in 2015, tackle graft, improve the investment climate and fight to protect Vietnam’s sovereignty.

Hiebert said Phuc would initially have a lower international profile than Dung, who stood up to China’s assertiveness in the South China Sea and sought tighter U.S. ties.

“Phuc will recognize that there’s broad consensus in Vietnam not to let Beijing push Hanoi around and hedge ties with China through closer relations with Washington,” he said.