United States Secretary of State Micheal Pompeo has said he is "saddened" by the death of
"Mr. Annan spent his life advocating for peace and human dignity during his long career at the United Nations.
"Even after leaving his post as Secretary-General he embodied the mission of the United Nations, by sowing the seeds of peace as Chair of The Elders, an independent group of global leaders committed to advancing the cause of peace and promoting human rights around the world.
"I join the international community in remembering his remarkable service to the world."
Mr Annan, the seventh UN General-Secretary and the first black African to hold that position, died in Switzerland on Saturday.
READ MORE: 10 things you didn't know about Kofi Annan
A statement from the family by the Kofi Annan Foundation said his wife and children were by him during his last days.
A week long national mourning has been declared by President Nana Akufo-Addo in his honour and the Ghana flag will also fly at half-mast during the period.
The Annan family has asked for privacy, saying funeral arrangements will be announced in due course.