"Today we have all lost a hero, a powerful champion for children," UNICEF said in a statement.
UNICEF said on Thursday it joined the world in mourning the death of former South African president Nelson Mandela.
"Today we have all lost a hero, a powerful champion for children," UNICEF said in a statement.
"The father of his nation, Nelson Mandela devoted much of his work to children."
It said Mandela had touched the lives of millions of children, which was a central part of his legacy.
UNICEF sent condolences to his wife Graca Machel, his family and South Africa.