UNITED NATIONS (AP) _ South Korea's Ban Ki-moon formally takes the reins of the United Nations Thursday as the institution grapples with internal reforms, volatility in the Middle East and international standoffs over the nuclear ambitions of North Korea and Iran.
Ban, who is being sworn-in before the General Assembly in a ceremony also honoring outgoing Secretary-General Kofi Annan, will not officially start his new job until Jan. 1, when he will become the eighth secretary-general of the 192-nation world body.
A 62-year-old career diplomat and former foreign minister of South Korea, Ban was unanimously elected to succeed Annan in October by the General Assembly, which by tradition rotates between regions in electing the secretary-general. Ban will become the first Asian to lead the world body in 35 years.
General Assembly President Sheikha Haya Rashed Al Khalifa will administer the oath of office to Ban, who will swear to conduct himself solely in the interests of the United Nations, and refuse to accept instructions from any government or other authority.
Ban will then make a statement to ambassadors and special guests.
In a speech after his election, Ban said his tenure ``will be marked by ceaseless efforts to build bridges and close divides,'' and to continue major reforms so the U.N. can meet the challenges of the 21st century.
``The true measure of success for the U.N. is not how much we promise, but how much we deliver for those who need us most,'' Ban said.
The General Assembly also is expected to adopt a draft resolution on Thursday paying ``warm tribute'' to Annan's ``exceptional contribution to international peace and security.''
The draft notes Annan's ``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.''
The resolution _ sponsored by Croatia, Grenada, Malaysia, Malta and Niger _ lauds Annan's ``many bold initiatives'' to reach U.N. goals of cutting extreme poverty in half, ensuring universal primary education by 2015, and promoting peace and security, environmental protections and U.N. reform.
Representatives from all the regional groups will then pay tribute to Annan, along with U.S. deputy ambassador Alejandro Wolff.
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.