Vietnam secured 192 out of a total of 193 votes, a record high number of votes. A candidate must secure at least two-thirds of all votes for a non-permanent seat in the council.
The country will replace Kuwait as a non-permanent member starting January 1, 2020.
President, Party Secretary Nguyen Phu Trong said the election is an "important recognition" of Vietnam's roles and contributions to global and regional affairs, showing its increased position and credibility.
"Vietnam becoming a non-permanent UN Security Council member is a big honor but also a heavy duty," Trong said in a statement on Friday.
He expressed confidence that Vietnam will fulfill the mission successfully, continuing to be a friendly and reliable partner to contribute to global efforts for sustaining peace, cooperation and development.
Vietnam was a non-permanent member for the 2008-2009 term, and acted as the council’s president in July 2008 and October 2009.
The UNSC consists of 15 member nations, in which five are permanent. Among the ten non-permanent members, five would be elected from Africa and Asian states, one from Eastern Europe states, two from Latin America and two from Western Europe and other states.
Five non-permanent members are elected each year on a regional basis to serve two-year terms.
The UNSC, one of the six principal organs of the United Nations, is charged with ensuring international peace and security, accepting new members to the United Nations and approving any changes to its charter.
Commenting on Asia-Pacific nations' decision to nominate Vietnam as the region's only candidate for the seat this year, James Borton, a nonresident fellow with the Stimson Center's Southeast Asia program, said the country's importance in international security has risen prominently since the successful Asia Pacific Economic Cooperation (APEC) summit in 2017.
He said Vietnam has won the world's acknowledgement for its leadership role in the ASEAN and is demonstrating its importance in the Indo-Pacific region.
With a non-permanent U.N. Security Council seat, Vietnam would surely maintain its openness and engagement with the world and with that responsibility, it would also up its engagement with the U.N. Peace keeping operations, he added.
Ian Martin, former executive director of Security Council Report, told VnExpress he hoped Vietnam would make a significant contribution to preventing conflicts, one of the major tasks of the council.
Vietnam’s experience in dealing with problems within the ASEAN, and post-conflict situations would be handy, he said.