The United Nations (UN) peacekeeping mission in Western Sahara expired on 31 October 2026 after the UN Security Council failed to agree on extending its mandate. This ended a mission established in 1991, raising concerns about military monitoring, unexploded ordnance(*1) and the future of negotiations over the status of the disputed territory.

The renewal failed after the United States and Russia vetoed each other’s proposals for Security Council resolutions regarding the peacekeeping mission. The US proposed renaming the United Nations Mission for the Referendum in Western Sahara (MINURSO) as MINUSO. The proposal would remove its mandate to organise a referendum on self-determination for the Sahrawi people(*2) in Western Sahara. Russia vetoed it, arguing that it favoured Morocco, the neighbouring country that controls most of Western Sahara. Russia then proposed a one-year extension under existing terms. The US vetoed that proposal.

Western Sahara, a territory in north-west Africa, became a Spanish colony in 1884. In 1975, Spain agreed to withdraw, and transferred administrative control to Morocco and Mauritania without settling the territory’s sovereignty. That year, the International Court of Justice (ICJ) found no established ties of territorial sovereignty between Western Sahara and either country and reaffirmed the population’s right to self-determination. Mauritania renounced its claim in 1979. Morocco maintained its claim, while the Polisario Front, a Sahrawi political and military movement supported by Algeria, fought for independence.

After 16 years of fighting, the parties agreed to a UN-brokered ceasefire in 1991. MINURSO was established to monitor the agreement and organise a referendum offering a choice between independence and integration with Morocco. The vote never occurred, with disagreements over voter eligibility obstructing preparations.

Morocco proposed autonomy in 2007, under which Sahrawis would manage internal affairs while Morocco would retain responsibility for defence and foreign relations. Polisario and Algeria rejected the proposal, insisting that independence remain an option.

Meanwhile, international support for Morocco’s position has expanded. The US recognised Moroccan sovereignty over Western Sahara in 2020 as part of an agreement under which Morocco established diplomatic relations with Israel. Between 2022 and 2025, Spain, France and the United Kingdom also backed Morocco’s autonomy plan. In 2025, the Security Council made Morocco’s autonomy plan the basis for future negotiations. Three subsequent rounds of talks failed to produce an agreement.

Morocco welcomed the failure to renew MINURSO and called for the Security Council to remove Western Sahara from its agenda. Polisario’s UN representative thanked Russia for blocking the US proposal, arguing that it threatened Sahrawi self-determination. Aid organisation Oxfam warned that losing MINURSO’s monitoring and de-escalation role could undermine stability in Western Sahara and threaten civilian safety.

(*1) Unexploded ordnance refers to explosive weapons, such as bombs, shells and landmines, that were used but failed to explode as intended. UN Mission helped clear these hazards along the 2,700-kilometre sand barrier separating areas controlled by Morocco and the Polisario Front in Western Sahara.

(*2) The Sahrawis are the indigenous people of Western Sahara. They share cultural and linguistic ties with communities in southern Morocco and neighbouring countries.

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MINURSO escorts visitors to the sand barrier in Western Sahara in 2009. (Photo: Teresa Marín/ Flickr [CC BY-NC-ND 2.0])