Org. Setting and Reporting The United Nations (UN) Office for the Coordination of Humanitarian Affairs (OCHA) is the UN Secretariat department responsible for bringing together humanitarian actors to ensure a coherent response to complex emergencies and natural disasters. OCHA also ensures that there is a framework within which each actor can contribute to the overall response effort. OCHA's mission is to mobilize and coordinate effective and principled humanitarian action in partnership with national and international actors in order to alleviate human suffering in disasters and emergencies; advocate the rights of people in need; promote preparedness and prevention and facilitate sustainable solutions.