Ban Ki-moon was sworn in Thursday as secretary general of the United Nations, pledging to work towards reuniting UN members while restoring the world body's "dynamic and courageous" entity.

"I look forward with a mixture of awe and enthusiasm to taking up my duties," Ban said following a ceremony at UN headquarters in New York.

UN Secretary General Kofi Annan shakes hands with his successor, Ban Ki-moon, in New York earlier this year.
(Osamu Honda/Associated Press)

Sheikha Haya Rashed Al Khalifa, president of the General Assembly, administered the oath of office to Ban, who swore to exercise his duties "in all loyalty, discretion and conscience," conduct himself solely in the interests of the UN, and refuse to accept instructions from any government or other authority.

The former South Korean foreign minister will become the eighth secretary general when he takes over from Kofi Annan on Jan. 1 following the UN's holiday break.

Ban also said he was "humbled to follow" Annan, who received a lengthy standing ovation Thursday from the 192-member general assembly as he took the podium as leader of the world body for the last time.

UN at crossroads

Ban, a 62-year-old career diplomat who was unanimously elected in October to succeed Annan, will become the first Asian to lead the UN since U Thant of Burma, now known as Myanmar, relinquished the title 35 years ago.

In a statement Thursday, Canadian Prime Minister Stephen Harper praised Annan for his stewardship.

"On his watch, the UN took on peacemaking as well as peacekeeping as part of its legitimate and necessary function to protect innocent people and preserve global security," Harper said.

'I hope this mission is not Mission Impossible.'— Ban Ki-moon on restoring trust in UN

Ban's tenure begins at a critical time for the organization during its 61-year history as it reels from scandal, war and heightened international division.  

The UN that Ban inherits is still in a state of reform in the wake of the Iraq oil-for-food scandal. It also faces questions on whether it is relevant or holds any weight in a world that has become so divided along political, economic and ideological lines.

"You could say I am a man on a mission, and my mission could be dubbed Operation Restore Trust," Ban said. "I hope this mission is not Mission Impossible."

Ban calls himself a 'pretty straight shooter'

In a press conference after the ceremony, Ban also addressed his perceived image as someone who lacked the frankness and determination to deal aggressively with the problems facing the world body.

"Your colleagues in Korea may have called me 'the slippery eel' because I was too charming for them to catch me," he said. "That nickname was given to me because I was too friendly to the media … I promise today I can be a pretty straight shooter when I have to."

The General Assembly also adopted a draft resolution paying "warm tribute" to Annan's "exceptional contribution to international peace and security."

The draft also pays tribute to "his outstanding efforts to strengthen the United Nations system, and to promote and protect human rights and fundamental freedoms for all, in the interest of a better world."

Annan, whose second five-year term ends at midnight on Dec. 31, has delivered a series of farewell speeches in the past weeks focusing on human rights, the elusive Mideast peace and relations with the United States.

With files from the Associated Press