Vietnam's one-party National Assembly has named a wartime prisoner of the former South Vietnamese government as the country's new president.

The assembly on Monday selected 62-year-old Truong Tan Sang, a former mayor and communist party chief in Ho Chi Minh City. Sang, the lone presidential candidate, held the communist party's number-two post since 2006. He is widely viewed a political rival of Prime Minister Nguyen Tan Dung, who is expected to retain his post in a similar election later this week.

Sang takes over the largely ceremonial position of president from Nguyen Minh Triet, who served a single term.

The 500-member assembly has been meeting since Thursday in its first session since being chosen in elections in May.

Sang was a student militant who fought for the North during the Vietnam War. He was imprisoned for two years in the early 1970s by the then U.S.-backed South Vietnam government.

On Saturday, the lawmakers selected Deputy Prime Minister Nguyen Sinh Hung as chairman of the assembly.

The delegates are expected to discuss the establishment of a committee to draft amendments to the 1992 constitution before their session concludes on August 6.