O’Brien will replace Valerie Amos, who served as under-secretary-general for humanitarian affairs and emergency relief coordinator for the past four years, earning high praise for her commitment in one of the UN’s most demanding posts.
The 57-year-old Conservative politician served as Prime Minister David Cameron’s envoy for the Sahel since 2012 and was parliamentary under-secretary of state for international development from 2010 to 2012.
The announcement was one of the most closely-watched appointments at the United Nations in recent years.