For the first time in more than three decades, the U.N. Security Council has failed to renew the mandate for its peacekeeping mission in North Africa’s disputed Western Sahara.

The vast mineral-rich desert territory, home to significant phosphate reserves and fishing resources, was a Spanish colony until 1975.

It is largely controlled by Morocco but has been claimed for decades by the Algeria-backed Polisario Front, and remains on the U.N. list of nonself-governing territories.