Morocco and the independence movement for Western Sahara, the Polisario Front, have agreed to UN-sponsored talks on the disputed territory.
The Polisario movement has been in dispute with Morocco for decades
The UN Security Council said it had asked both sides in the 32-year-old dispute to negotiate unconditionally.
Morocco's sovereignty over the mineral-rich region is contested by Polisario, an Algerian-backed separatist movement.
The former Spanish colony was annexed by Morocco after Madrid left in 1975.
"We want negotiations to start unconditionally and I am happy that all sides have agreed to do that," US Ambassador Zalmay Khalizad told reporters.
But he said both sides had accepted the resolution, which also renewed the mandate of the 220-strong UN peacekeeping force, somewhat "reluctantly".
Morocco's ambassador to the UN, El Mostafa Sahel, said the resolution brought in, "a new process of negotiation, a new way to reach a negotiated political solution of this question".
Spain's foreign ministry expressed hopes that the talks would lead to "a politically just, lasting and mutually acceptable solution that includes the self-determination of the people of the Western Sahara".
Morocco recently offered partial control to the region through its own legislative, executive and judicial institutions.
But this proposal was rejected by the Sahrawis who said they sought "the right of the people to self-determination."
Western Sahara was seized by Morocco and Mauritania in 1975 after the colonial power, Spain, pulled out.
Fighting erupted the following year, and Morocco took over most of the region after Mauritania withdrew in 1978.