 Mulet served as the United Nations Special Representative for Haiti from 2005 to 2007.On 27 July 2007, United Nations Secretary-General Ban Ki-moon announced his intention to appoint Mulet as Assistant Secretary-General for Peacekeeping Operations, effective 1 September.On 31 March 2010, Mulet was appointed by the United Nations Secretary-General Ban Ki-moon as his Special Representative and Head of the United Nations Stabilization Mission in Haiti (MINUSTAH).