Carter and Annan spoke to The Associated Press today after arriving in Johannesburg, ahead of a major planned memorial for Mandela that will draw some 100 world leaders and tens of thousands of mourners.
They are part of The Elders, an independent group of world leaders and human rights activists. Mandela became the group's honorary chairman after its founding in 2007 but was never an active member.
Annan said of Mandela: "The way he lived his life and what he did also should convey the message to each and every one of us that as individuals, we have power.