Human rights group The Elders on Saturday expressed their shock and deep sadness at the death of Kofi Annan, who previously served as the organisation's chair.
"We are devastated at the loss of our dear friend and fellow Elder," said The Elder's Deputy Chair Gro Harlem Brundtland in a statement.
"Kofi was a strong and inspiring presence to us all, and The Elders would not be where it is today without his leadership. Throughout his life, Kofi worked unceasingly to improve the lives of millions of people around the world.
"While we mourn his passing today, we resolve as Elders to continue to uphold his values and legacy into the future".
Describing his role in The Elders as "vital", the organisation said he was "a voice of great authority and wisdom in public and private, most recently on visits to South Africa and Zimbabwe in July 2018".
Annan, who served as United Nations Secretary-General from 1997 until 2006, succeeded Desmond Tutu as chair of the elders in 2013.
The Elders described how he was "globally admired and respected" in this leadership position.
Annan's death, following a short illness, was announced earlier on Saturday. Condolences were extended to Annan's family by The Elders.
The Elders is a group of former world leaders that was originally founded by Nelson Mandela. Mandela's widow Graca Machel and Archbishop Emeritus Desmond Tutu continue to serve on it.