The UN General Assembly on Thursday appointed Antonio Guterres as the new secretary-general of the United Nations, in a shift towards a more high-profile leadership of the world body.
The 193 member states adopted by consensus a resolution formally naming the former prime minister of Portugal as UN chief for a five-year term beginning January 1.
The socialist politician, who also served as UN refugee chief for a decade, is expected to play a more prominent role as the world's diplomat-in-chief than Ban, the South Korean who will step down after two five-year terms.
Guterres was greeted by loud applause as he entered the packed hall following the vote and was to deliver his first address as incoming UN chief during the session.
Following the vote, Ban told the assembly that Guterres was well-known in diplomatic circles as a man of compassion during his decade as UN high commissioner for refugees.
"He is perhaps best known where it counts most -- on the frontlines of armed conflict and humanitarian suffering," said Ban.
"His political instincts are those of the United Nations -- cooperation for the common good, and shared responsibility for people and the planet."
Guterres won unanimous support from the Security Council during a vote last week that capped the most transparent campaign ever held at the United Nations for the top post.
The 67-year-old polyglot campaigned on a pledge to promote human rights and enact reforms within the UN system, seen as clunky and too slow to respond to unfolding disasters.
His appointment comes at a time of global anxiety over the ongoing war in Syria, the refugee crisis and raging conflicts in South Sudan and Yemen.
The Security Council is deadlocked over Syria after two draft resolutions were defeated in separate votes over the weekend, one of which was vetoed by Damascus ally Russia.
French Ambassador Francois Delattre has described Guterres as the "best possible captain during this stormy period" of global crises, praising him as a reformer, a unifier and a "humanist with a genuine moral compass."
"Guterres has shown as head of UNHCR that he is a man who seeks human contact and is hands-on," he said.
As Portugal's prime minister from 1995 to 2002 and as UN high commissioner for refugees from 2005 to December 2015, Guterres demonstrated that "he is a reformer," said British Ambassador Matthew Rycroft.
"He is able to do both the outward leadership, the vision, the inspiration, the setting of direction but also the internal reform to drive efficiency, to improve processes and to make the whole more than the sum of its parts," he said.
Some of the buzz generated by Guterres' appointment stems from disappointment with Ban, a chief many saw as a poor communicator who showed a reluctance to take strong action on the biggest crises.
"Everyone is very polite about Ban but let's face it... everyone knows that he has not been a strong secretary-general in terms of either internal reform or external leadership," said a Security Council diplomat.
"He has the right instincts on Syria and everything else, but he hasn't had the ability to really drive international opinion on any of these issues," said the diplomat, who spoke on condition of background.
Diplomats said they expect Guterres to spend his first 100 days in office focused on boosting the role of the secretary-general.
"I am not saying he will have a particular plan to bring peace to Syria, but I think that he will be focused on making sure that there is space for the secretary-general to be centrally involved on those biggest issues," said the diplomat.
Guterres will move into an office with his transition team in downtown Manhattan, just across from UN headquarters.