The U.N. Security Council has approved a resolution welcoming "the new momentum" in efforts to end the decades-old dispute over the mineral-rich Western Sahara, but Morocco and the pro-independence Polisario Front remain at odds over its future.

South Africa and Russia abstained in Tuesday's 13-0 vote, calling the resolution unbalanced.

Last year, the Security Council called for accelerated efforts to reach a solution to the more-than-four-decade standoff over the territory, but two rounds of talks have made no headway.

Morocco insists on wide-ranging autonomy for Western Sahara while the Polisario Front insists the local population has the right to a referendum on its future.

Morocco annexed the former Spanish colony in 1975 and fought the Polisario Front until the United Nations brokered a cease-fire in 1991.