Antonio Guterres pledged on Thursday to be an "honest broker" and "bridge-builder" on global issues after the United Nations General Assembly unanimously voted to appoint him as the next secretary-general of the world body.

The former prime minister of Portugal and UN refugee chief will replace outgoing Secretary-General Ban Ki-moon on January 1 as the world faces conflicts from Syria and Yemen to South Sudan, refugee and humanitarian crises, climate change and development challenges.

Guterres was welcomed with applause after the vote as he told the General Assembly that he was "fully aware of the challenges the UN faces and the limitations of the secretary-general."

"The dramatic problems of today's complex worldcan 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 makes his good offices available ... to help find solutions that benefit everyone involved," he told the chamber of 193 member-states. The 67-year-old socialist politician will serve a five-year term.

On Syria, the most pressing crisis facing the UN, Guterres said world powers must overcome differences to resolve a burning conflict that has killed nearly 400,000 people and displaced millions as it remains a threat to world peace.

"Whatever divisions might exist, now it's more important to unite," Guterres told reporters after the vote that will make him the ninth secretary-general of the world body. "It's high time to fight for peace."

His call comes as the United States and Russia, alongside Turkey, Qatar and Saudi Arabia were set to meet in the Swiss city of Lausanne on Saturday to discuss the Syrian crisis. Washington will then meet with its European partners on Sunday in London in a bid to give renewed momentum to talks to end the conflict after two recent Security Council resolutions on Syria were squashed.

Guterres also said "diversity can bring us together not drive us apart," warning that the world community must unite against terrorism and a rise of xenophobic populism.

"We must make sure that we are able to break this alliance between all those terrorist groups, or violent extremists on one side, and the expressions of populism and xenophobia on the other side. These two reinforce each other, and we must be able to fight both of them with determination," he said.

The incoming UN chief has pledged to improve the gender make-up of the UN, where women currently hold only 25 of senior positions.

Guterres won the unanimous support of the Security Council last week after six rounds of informal polls placed him first among 13 potential candidates. In his campaign, he pledged to promote human rights and enact reforms within the UN system, often perceived as being slow in responding to disasters.

The president of the UN General Assembly, Peter Thomson, praised the transparent selection process, saying, "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."

Secretary-General Ban said Guterres, who served between 2005 and 2015 as the High Commissioner for Refugees, is "best known where it counts most, on the front lines of armed conflict and humanitarian suffering."

US President Barack Obama said in a statement that Guterres "had the character, vision and skills needed to lead the United Nations at this critical moment."

German Chancellor Angela Merkel pledged her country's support for the United Nations and congratulated Guterres, saying "your selection reflects the appreciation you have received in the United Nations, based on your particular commitment to people, not least as a High Commissioner for Refugees."

Russian President Vladimir Putin called Guterres to wish him success "in this important and demanding position."

French President Francois Hollande said the world needs a strong United Nations and praised Guterres for his ability to "set a course of action, show leadership and enact reforms."

cw/xx (AFP, AP, Reuters)