File Photo for UN Security Council.
The UN Security Council on Friday called on South Sudan's warring sides to immediately begin a ceasefire agreed as part of a new peace deal and threatened sanctions against those who undermine the accord.
Under the terms of the peace deal, the ceasefire is due to come into effect on Saturday, but President Salva Kiir has already ordered his troops to halt operations and remain in their barracks.
In a unanimous statement, the 15-member council called on the sides "to adhere to the permanent ceasefire immediately" as outlined in the agreement to end the 20-month conflict in South Sudan.
The council expressed "its readiness to consider appropriate measures" including "an arms embargo and additional targeted sanctions."
Facing the threat of international sanctions, Kiir signed the deal on Wednesday but annexed a list of reservations that he said would have to be addressed for the deal to take hold in the world's youngest nation.
Rebel leader Riek Machar had signed the deal a week earlier.
Fighting erupted in December 2013 when Kiir accused Machar of planning a coup, unleashing a wave of killings that has split the country along ethnic lines.
At least seven ceasefires have already been agreed and then shattered within days or even hours.
The deal gives the rebels the post of first vice president, which means that Machar would likely return to the job from which he was sacked in July 2013, an event which put the country on the path to war later that year.
Tens of thousands of people are thought to have died in a war marked by ethnic killings, gang rapes and child soldier recruitment.
The council said that those responsible for human rights violations must face justice.
Some 2.2 million people have been driven from their homes in the conflict. About 200,000 terrified civilians are sheltering at UN bases.
The United States has presented a draft UN resolution imposing an arms embargo and targeted sanctions on individuals who block provisions of the peace accord.