The presidents of Namibia, Liberia, Ivory Coast, Ethiopia and Sierra Leone attended, along with Niger's prime minister and Angola's vice president.

Former leaders from Europe and Africa also joined the ceremony, including Graca Machel, wife of the late South African President Nelson Mandela.

Gutteres said the late Annan "was an exceptional global leader — and he was also someone virtually anyone in the world could see themselves in: those on the far reaches of poverty, conflict and despair who found in him an ally; the junior UN staffer following in his footsteps; the young person to whom he said until his dying breath 'always remember, you are never too young to lead — and we are never too old to learn.'"

Guterres, who was selected by Annan to be the UN High Commissioner for Refugees, spoke of the honor of working with him to weather "many of the same global storms."

"The world has lost a standard-bearer of global cooperation. The United Nations has lost an embodiment of its mission," he said. "Now that I occupy the office Kofi once held, I am continually inspired by his integrity, dynamism and dedication. To him, indifference was the world's worst poison."

Even after serving as secretary-general he continued to work on the front lines of diplomacy, said Guterres.