Kofi Annan, a former United Nations secretary-general, died Saturday, the Annan family and the Kofi Annan Foundation confirmed. He was 80 years old.
"Kofi Annan, former Secretary General of the United Nations and Nobel Peace Laureate, passed away peacefully," after a "short illness," they said in a statement that was tweeted. The illness was unspecified.
Annan, from Ghana, won the Nobel Peace Prize for his far-reaching humanitarian work in 2001.
He was also the first black African to serve in the U.N. role as the world's top diplomat, the BBC reported.
He served two terms, from Jan. 1, 1997 to Dec. 31, 2006.
Antonio Guterres, the current U.N. secretary-general, issued a statement on Annan's passing.
"Kofi Annan was a guiding force for good. It is with profound sadness that I learned of his passing. In many ways, Kofi Annan was the United Nations," Guterres said. "He rose through the ranks to lead the organization into the new millennium with matchless dignity and determination."
Guterres sent his heartfelt condolences to the "proud son of Africa who became a global champion for peace and all humanity."
"Kofi Annan was not just a great breaker of glass ceilings, he was a leader and a visionary, who worked to foster international cooperation and a more united world," David Lammy, a British member of Parliament tweeted.
"One of the first people I met after arriving in Ghana, so shocked to hear of the passing of Kofi Annan. A remarkable man. Gone too soon," Iain Walker, British High Commissioner to Ghana, tweeted.
During his tenure, Annan presided over some of the worst failures and scandals at the world body, one of its most turbulent periods since its founding in 1945.
Annan was chief architect of what became known as the Millennium Development Goals, and played a central role in creating the Global Fund to Fight AIDS, Tuberculosis and Malaria and the U.N.'s first counter-terrorism strategy.
He also had special assignments. After Iraq invaded Kuwait in 1990, he facilitated the repatriation from Iraq of more than 900 international staff and other non-Iraqi nationals, and the release of western hostages in Iraq. He led the initial negotiations with Iraq for the sale of oil in exchange for humanitarian relief.
As special envoy to Syria in 2012, Annan won international backing for a six-point plan for peace. The U.N. deployed a 300-member observer force to monitor a cease-fire, but peace never took hold and Annan was unable to surmount the bitter stalemate among Security Council powers. He resigned in frustration seven months into the job, as the civil war raged on.
He remained a vocal commentator on troubles like the refugee crisis; promoted good governance, anti-corruption measures and sustainable agriculture in Africa; and pushed efforts in the fight against illegal drug trafficking.
At a farewell news conference, Annan listed as top achievements the promotion of human rights, the fighting to close the gap between extreme poverty and immense wealth, and the U.N. campaign to fight infectious diseases like AIDS.
Annan retained connections to many international organizations. He was chancellor of the University of Ghana, a fellow at New York's Columbia University, and professor at the Lee Kuan Yew School of Public Policy in Singapore.
Annan is survived by his wife Nane and their children Ama, Kojo and Nina.
Former President George W Bush released a statement saying: "Laura and I send our sympathies to Nane and the Annan family on the passing of Kofi Annan. Kofi was a gentle man and a tireless leader of the United Nations. His voice of experience will be missed around the world."
The Associated Press contributed to this report.