The U.N. Security Council says it is ready to impose sanctions on South Sudan's warring factions if they do not fully implement a new peace agreement.
In a presidential statement Friday, the 15-member council called for the sides to adhere to the cease-fire immediately.
South Sudan's President Salva Kiir ordered the army to halt all military operations on Thursday, before a full cease-fire goes into effect Saturday.
Kiir signed a peace agreement with rebel forces in Juba on Wednesday, a week after rebel leader Riek Machar signed the agreement in Addis Ababa. But Kiir annexed a list of reservations about the deal, raising fears the cease-fire may not hold.
UN underscores point
The U.N. statement said it was concerned by "any statement by any party suggesting a lack of commitment to implement the agreement."
It said the council is ready "to consider appropriate measures" to ensure the full implementation of the peace agreement, including "the imposition of an arms embargo and additional targeted sanctions."
The peace deal follows months of negotiations hosted by Ethiopia and several broken cease-fire agreements.
South Sudan is the world's youngest country, winning independence from Sudan in 2011. Fighting between government forces and Machar's rebels broke out in December 2013 and has been especially brutal on civilians.
Thousands have been killed and about 2.2 million driven from their homes. Millions are in desperate need of food.