Ghanaian President Nana Akufo-Addo (4th L, front) and United Nations Secretary-General Antonio Guterres (3rd L, front) attend the state funeral of former UN Secretary-General Kofi Annan in Accra, Ghana, on Sept. 13, 2018. A number of African and world leaders joined Ghanaian President Nana Akufo-Addo here on Thursday to bid farewell to former United Nations Secretary-General Kofi Annan, who passed away in Switzerland on Aug. 18. (Xinhua/Fred Bonsu)

Soldiers escort the casket of former UN Secretary-General Kofi Annan during Annan's state funeral in Accra, Ghana, on Sept. 13, 2018. A number of African and world leaders joined Ghanaian President Nana Akufo-Addo here on Thursday to bid farewell to former United Nations Secretary-General Kofi Annan, who passed away in Switzerland on Aug. 18. (Xinhua/Fred Bonsu)

Nane Annan (2nd R, front), widow of former United Nations Secretary-General Kofi Annan, lays a wreath during Annan's state funeral in Accra, Ghana, on Sept. 13, 2018. A number of African and world leaders joined Ghanaian President Nana Akufo-Addo here on Thursday to bid farewell to former United Nations Secretary-General Kofi Annan, who passed away in Switzerland on Aug. 18. (Xinhua/Fred Bonsu)

United Nations Secretary-General Antonio Guterres (1st L) lays a wreath for his late colleague Kofi Annan during Annan's state funeral in Accra, Ghana, on Sept. 13, 2018. A number of African and world leaders joined Ghanaian President Nana Akufo-Addo here on Thursday to bid farewell to former United Nations Secretary-General Kofi Annan, who passed away in Switzerland on Aug. 18. (Xinhua/Fred Bonsu)

Ghanaian President Nana Akufo-Addo (2nd L) lays a wreath for former UN Secretary-General Kofi Annan during Annan's state funeral in Accra, Ghana, on Sept. 13, 2018. A number of African and world leaders joined Ghanaian President Nana Akufo-Addo here on Thursday to bid farewell to former United Nations Secretary-General Kofi Annan, who passed away in Switzerland on Aug. 18. (Xinhua/Fred Bonsu)