Portugal's Antonio Guterres has been officially appointed as the next UN secretary-general on Thursday (13 October). He will take over from Ban Ki-moon when his second five-year term ends on 31 December.

He was chosen following a unanimous decision by the 15-nation Security Council last week from among 13 candidates. Sixty-seven-year-old Guterres was the prime minister of Portugal from 1995 to 2002 and led the UN refugee agency UNHCR for 10 years from June 2005 to December 2015.

"I believe this process means that the true winner today is the credibility of the UN. And it also made very clear to me that, as Secretary-General, having been chosen by all Member States, I must be at the service of them all equally and with no agenda but the one enshrined in the UN Charter," said Guterres.

He pledged to make efforts to restore peace in the world and alleviate the suffering of vulnerable people, especially refugees fleeing conflict zones. He said ending the conflict in Syria would be his biggest challenge and remain his top priority, besides gender equality.

"I believe it is the international community's first priority is to be able to end this conflict and use this momentum created by it to try to address all the other conflicts that are interlinked," he told the BBC.

Guterres warned that the world is facing a dangerous time and urged the international community to work together to ensure a safe future for all. He highlighted the importance of setting aside difference of opinions and interests to understand that there is a common concern to end conflicts.

Addressing the UN General Assembly, he said: "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."

"One in which the secretary general make his good offices available, working as a convenor, a mediator, a bridge-builder and an honest broker to help find the solutions that benefit everyone involved."

As the chief of the UN refugee agency, Guterres is reported to have led the global body through some of the worst refugee crises in Syria, Iraq and Afghanistan, constantly appealing to Western powers to do more to help accommodate refugees.

He was lauded by Ban who described his successor as "a superb choice" for the position as the ninth UN chief. "He is perhaps best known where it counts most — on the frontlines of armed conflict and humanitarian suffering," Ban said of Guterres. "His political instincts are those of the United Nations — co-operation for the common good and shared responsibility for people and the planet."