FILE - A Sahrawi refugee boy stands in the shadow in the Boujdour refugee camp, Oct. 11, 2021. Bernat Armangue/AP hide caption

Bernat Armangue/AP

CASABLANCA, Morocco — The U.N.'s long-running peacekeeping mission for the disputed Western Sahara ceased operations Sunday after 35 years, as a result of a U.S.-Russia standoff at U.N. headquarters over the territory's future.

The end of the mission raises concerns about stability in the region. Rich in minerals and fisheries, Western Sahara is a vast desert territory roughly the size of Colorado along Africa's northwestern Atlantic coast. Once ruled by Spain, it is claimed by both Morocco and the pro-independence Polisario Front.

"This 1 November 2026 marks the start of the liquidation period," Stéphane Dujarric, spokesperson for the U.N. secretary general, said in a statement.…