Former Portuguese prime minister Antonio Guterres is set to start a five-year term as UN secretary general in January after the UN General Assembly formally approved him for the job on Thursday.
The 193-member assembly passed a resolution by consensus to officially approve a recommendation from the 15-member UN Security Council, which had previously moved to appoint Guterres.
Peter Thomson, president of the UN General Assembly, praised the transparent selection process that led to the election of Guterres, who had formerly served as the head of the UN refugee agency.
"I'm confident that Mr Guterres will serve the global community with dedication as a moral authority and be the voice of our moral conscience and humanity throughout his term," Thomson said.
Guterres will replace current UN chief Ban Ki-moon of South Korea, whose second term is coming to an end in December after serving 10 years in the post.
During the election process, which for the first time in the UN's 71-year history included open hearings with all 13 candidates, Guterres emerged as a well-spoken and experienced leader with thorough knowledge of international affairs and the UN system.
Guterres, who has also been praised for his language skills, thanked UN member states for electing him on Thursday - addressing the assembly in English, French and Spanish, which are three of the UN's six official languages.
He promised to be "a convener, a mediator, a bridge-builder and an honest broker" in a world facing large challenges.
"The dramatic problems of today's complex world can only inspire a humble approach - one in which the secretary general alone neither has all the answers, nor seeks to impose his views," he said.
Guterres later told reporters that he felt "deep solidarity" with the Syrian people who have been swept up in the largest humanitarian crisis currently faced.
"I'll do my best to serve the cause of peace for the Syrian people," he said.
Ban called Guterres a "wonderful choice to steer" the UN, welcoming his successor in four languages - English, French, Spanish and Guterres' native Portuguese.
"Above all, Mr secretary general designate, congratulations, félicitations, felicitaciones, parabens!" Ban said.