The U.N. Security Council has unanimously adopted a resolution setting up a system to impose sanctions on South Sudan in the hope that it will press rivals leaders into ending a conflict that has killed tens of thousands.

The resolution drafted by the United States says an arms embargo is possible if the warring sides can't stick to a peace deal.

The resolution doesn't explicitly name South Sudan President Salva Kiir or rebel leader Riek Machar as possible targets for sanctions that would include an asset freeze and travel ban.