United Nations Secretary-General Antonio Guterres signs a book of condolences in memory of the late former Secretary-General Kofi Annan, at the UN headquarters in New York, Aug. 22, 2018. A wreath-laying ceremony was held at UN Headquarters in New York on Wednesday to mourn the death of former UN Secretary-General Kofi Annan. Annan, a Ghanaian diplomat, died on Saturday in Switzerland. He served as UN secretary-general for 10 years till the end of 2006. (Xinhua/Li Muzi)