The mission, known as MINURSO, has been in place since a UN-brokered ceasefire in 1991. November 1 would mark the start of its liquidation phase, with assets transported back to troop-contributing countries, Guterres said in a statement.
Morocco, which claims Western Sahara as its own, welcomed the decision, while its opponents in the Algeria-backed Polisario Front expressed concern. The Polisario Front has been seeking an independent state in Western Sahara since former colonial power Spain left in 1976.
The end of the mission comes a year after the Security Council adopted a US-drafted resolution that accepted Rabat's plan to give the territory autonomy under Moroccan sovereignty as the most feasible solution to the conflict, according to the report.
What happens next is uncertain. The withdrawal of peacekeepers removes a long-standing buffer and monitoring presence in a dispute that has lasted half a century. Diplomats will be watching whether the political process can fill the gap left by MINURSO, or whether tensions rise once the liquidation phase is complete.