Ban Ki-moon, taking the oath of office to become the eighth U.N. secretary-general starting Jan. 1, 2007, placed his left hand on the 61-year-old world organization's charter, beginning famously "We the peoples ... " and raised his right hand, standing before the green marble dais of the U.N. General Assembly.

"To illustrate my faith in the charter, today I asked the secretariat to create a new practice by placing my left hand on the charter while taking my oath," he said in his opening remarks Thursday in the assembly's Great Hall.

Taking the oath, administered by General Assembly President Sheikha Haya al-Khalifa, Ban swore "to discharge these functions and regulate my conduct with the interests of the United Nations only in view, and not to seek or accept instructions in regard to the performance of my duties from any government or other authority external to the organization."

His innovation in ceremony may be taken as an indicator he is more a man of action than his soft-spoken, man-of-humility demeanor suggests, a man who is no slave to tradition. Ban has in the past said he was a man of action despite the soft image.

After all, shortly afterwards in a meeting with reporters, he said, "I can be a pretty straight shooter when I need to."

Ban wasn't the only man honored Wednesday at U.N. World Headquarters in New York.

A General Assembly "Tribute" resolution was approved by a nearly one minute-standing acclamation for Secretary-General Kofi Annan.

"His career has been unique," the General Assembly president said. "He has risen through the ranks of the United Nations and devoted his life's service to the organization. So, today we are not only bidding farewell to the current secretary-general, but also to one of the longest serving officials of the United Nations."

She said Annan has stood at the helm as the world organization became a more effective global actor and demands for its services have grown over the past 10 years.

Representatives of the various regional groups praised Annan's role in facing the many challenges confronting the world at large and the United Nations itself by promoting peace, humanitarian aid, human rights, development for the under-developed, and wide-ranging reform for the world organization.

Annan said despite many difficulties and some setbacks in the past decade "we have achieved much that I am proud of," citing U.N. reforms in particular.

"(The U.N.) became more transparent, accountable and responsive," he said. "It began to better address the needs of individuals worldwide. It faced emerging threats, as well as familiar ones, head-on.

"It internalized the notion that development, security and human rights must go hand in hand; that there can be no security without development and no development without security, and neither can be sustained in the longer term without being rooted in the rule of law and respect for human rights," said Annan, a Ghanaian who was often praised as a "son of the soil" of Africa.

"I depart convinced that today's United Nations does more than ever before, and does it better than ever before," he said. "Yet our work is far from complete, indeed, it never will be."

After he spoke, Annan again received a standing ovation, but this time for nearly 90 seconds. He steps down Dec. 31.

"I am confident that leading by example Ban Ki-Moon has what it takes to make a great contribution to the organization and the global public that it lives to serve," the General Assembly president said.

Ban pledged to seek the highest ethical standards and paid tribute to his predecessor's leadership in guiding the United Nations through challenging times and ushering it into the 21st century.

"Secretary-General Annan ... It is an honor to follow in your revered footsteps," he said.

Ban said one of his core tasks will be "to breathe new life and inject renewed confidence into the sometimes weary Secretariat" and improve human resource management, underlining the United Nations needs a "dynamic and bold" Secretariat, not a "passive and fearful" one.

He pledged to restore trust as a "harmonizer and bridge-builder."

Trust, Ban later explained in his session with reporters, had to be built between member states and between member states and the Secretariat.

"By strengthening the three pillars of our United Nations -- security, development and human rights -- we can build a more peaceful, more prosperous and more just world for succeeding generations," he said. "I will do everything in my power to ensure that our United Nations can live up to its name, and be truly united, so that we can live up to the hopes that so many people around the world place in this institution."

Ban also promised to keep at the top of his concerns, the Darfur region of Sudan and other Africa conflicts, the Middle East, the six-party talks on North Korea and continuing U.N. reform.