Russia vetoed a U.S.-drafted resolution Friday that would have supported Morocco’s demand for sovereignty over the disputed Western Sahara and ended the U.N.’s 35-year peacekeeping mission, which was charged with helping to prepare a referendum on the future of the mineral-rich territory.

The U.N. Security Council then defeated a Russian-drafted resolution to extend the mandate of the peacekeeping mission for a year. The 3-1 vote with 11 abstentions meant the United States didn’t have to use its veto because the resolution failed to get the minimum nine “yes” votes in the 15-member body.

The U.N.…