The United Nations Mission for the Referendum in Western Sahara (MINURSO) was established by Security Council resolution 690 (1991) of 29 April 1991, in accordance with "the settlement proposals", as accepted on 30 August 1988 by Morocco and the Frente Popular para la Liberación de Saguia el-Hamra y de Río de Oro (Frente POLISARIO). The Secretary-General's implementation plan, approved by the Security Council, provided for a transitional period during which the Special Representative of the Secretary-General would have sole and exclusive responsibility over all matters relating to a referendum in which the people of Western Sahara would choose between independence and integration with Morocco. The Special Representative would be assisted in his tasks by a deputy special representative and by an integrated group of United Nations civilian, military and police personnel, to be known as the United Nations Mission for the Referendum in Western Sahara.

MINURSO has been mandated to:

• Monitor the ceasefire;
• Verify the reduction of Moroccan troops in the Territory;
• Monitor the confinement of Moroccan and Frente POLISARIO troops to designated locations;
• Take steps with the parties to ensure the release of all Western Saharan political prisoners or detainees;
• Oversee the exchange of prisoners of war (International Committee of the Red Cross);
• Implement the repatriation programme (United Nations High Commissioner for Refugees);
• Identify and register qualified voters;
• Organize and ensure a free and fair referendum and proclaim the results.