Former governor general Adrienne Clarkson is remembering her friend and ex-United Nations secretary-general Kofi Annan as “a man of enormous compassion” and “intense human vulnerability.”

The first black African to lead the United Nations, Annan died at the age of 80 after a short illness, his family and foundation announced on Saturday.

The relationship between Clarkson and Annan spanned a quarter of a century and the pair served together on the board of directors for the Global Centre for Pluralism in Ottawa.

“I think that what was remarkable about Kofi Annan was that he hereditarily -- and for centuries I guess, because that’s the way African tribal life is -- was really a king and a prince in his own culture,” Clarkson said. “He brought all of the best qualities of that to his international work in the modern world for the UN.”

Those qualities, Clarkson said, included dignity, generosity, understanding, compassion and a capacity for listening that “is very rare in world leaders.”

She added that Annan was not “a power technocrat” and that while he was realistic in his assessment of the world’s most complex problems, “he never lost hope and he never became cynical.”

Clarkson last spoke to Annan six weeks ago and said that he was his typical courteous and helpful self.

“He sounded fine on the phone,” she told CTV News’ Omar Sachedina by phone. “It’s such a shock that he died because I had no idea he was unwell.”

Clarkson joins a number of other Canadians who have offered condolences following the death of the celebrated diplomat, who won the Nobel Peace Prize in 2001 for helping to revitalize the UN.

Prime Minister Justin Trudeau offered his condolences on social media, tweeting that “it’s now up to all of us to carry his work forward.”

In a statement released later in the day, Trudeau lauded the Ghanian’s career at the UN and the work of his foundation.

“He believed deeply in the power and potential of young people,” the statement said. “He recognized their innate sense of a world that has never been more interconnected or interdependent, and knew that young people, in many ways, had more to teach us than we had to teach them.”

Former prime minister Paul Martin told The Canadian Press that Annan had a great love and affection for Canada and that his greatest legacy was his leadership in promoting the importance of multilateral institutions in a globalizing world.

Michaelle Jean, the former governor general, also expressed her respect for Annan, calling him a "tireless peacemaker."

"From my friend #KofiAnnan, who saw the world fall into horror, I retain this confession, his dilemma: 'How can the (United Nations) defend its raison d'etre if it fails to stand up in the defence of human rights above all?"' she wrote in French on her official Twitter account.

Annan is survived by his wife and three children. Funeral arrangements have not been announced.

With a report from CTV News' Omar Sachedina and The Canadian Press