The top UN aid official in South Sudan has called on the two warring parties to open access for aid after they signed a new peace deal, the conflict's second.
Toby Lanzer called on the government and rebel fighters to open roads for truck convoys and rivers for barges to allow emergency aid through.
The peace deal calls for unhindered humanitarian access and a cessation of hostilities within 24 hours.
A January peace deal signed by the government of President Salva Kiir and rebels backing former vice president Riek Machar fell apart immediately. Fighting began in December.
John Prendergast of the Washington-based Enough Project said the world will learn quickly whether this one holds. He said the two sides are poised to attack in several volatile locations.