President Maria Fernanda Espinosa of the 73rd General Assembly session, which just began last week, said it is "eminently fitting that we remember him (Annan) on this day -- a day fixed by this Assembly 17 years ago, on his watch and with his strong support, as International Peace Day. For no one labored more tirelessly or consistently in the cause of peace than did Kofi Annan."

"Kofi Annan was a great Secretary-General because he understood that peace cannot be achieved in isolation," she said.

Nane Annan said her late husband, "died too soon," shortly after returning from witnessing elections in Zimbabwe, just another one of the many missions he was on since "retiring" at the end of 2006.

"The rebel on the 38th floor," where the secretary general's office is located, had a "glowing aura" and was known for thinking "outside the box," she said, expressing gratitude for the memorial and adding, "We shall cherish this moment."

The late UN chief's son, Kojo Annan, in stepping behind the green marble podium where heads of state and government will stand next week to deliver speeches during the assembly's annual General Debate, said, "this is hallowed ground."

Hallowed, because it is "the only place on the planet" considered "home" for all world leaders, he said.

Recalling his father's legacy and afforded the privilege of being called a "World Citizen," Kojo Annan said it meant "completely embracing the common humanity of all of the world's citizens; it's about seeing potential in anyone and helping build a world where anything is possible for that someone."

"It's literally unfathomable that an obscure young man born in Kumasi, Ghana's second city, 19 years before Ghana's independence and who had never left the country before he was 18, would rise one day to become the 7th secretary-general of the United Nations, and yet that was my father's story," he said.

Ghana Ambassador Annan Cato, speaking for Nana Addo Dankwa Akufo-Addo, president of Ghana, said "the outpouring of tributes to the life and work of Kofi Annan this morning has again reminded us of some of the contours in the foot-prints he left as he walked the globe."

"It is Ghana's hope that these foot-prints will serve as a guiding light for future generations," Cato said. "It is also our hope that a fitting tribute and memorial to Kofi Annan will be the reinforcement of our collective commitment to the urgent work of the United Nations in addressing the challenges of today's world."

Citing the opening words of the UN Charter the Accra envoy said, "We the Peoples' was Kofi Annan's mantra."