UN-Sonderbeauftragter
In 2008, Landgren became Deputy Special Representative of the Secretary-General to Nepal, under Special Representative Ian Martin. Following the renewal of UNMIN's mandate in 2009, Landgren replaced Martin as the head of the UN mission.. From 2011 to 2012, she was head of the United Nations Mission in Burundi. From 2012 to 2015, she served as the Special Representative of the Secretary-General to Liberia and head of the United Nations Mission in Liberia. She led UNMIL's response to the 2014 Ebola outbreak in Liberia.