Malcorra served as the United Nations Under-Secretary-General for Field Support. She was appointed by Secretary-General Ban Ki-moon in March 2008, succeeding Jane Holl Lute. Prior to that, she had been chief operating officer and deputy executive director of the World Food Programme, where she oversaw emergency and humanitarian operations in more than 80 countries. During the tsunami emergency in December 2004, she led the first phase of the operational response and mustered human resources, budget, finance, information, technology, telecommunications, administration and security to deal with the disaster.