South Sudan’s President Salva Kiir and rebel leader Riek Machar have agreed a peace deal after a five-month conflict.
The deal calls for an immediate truce and the formation of a transitional government ahead of the drafting of a new constitution and new elections.
The conflict in the world’s newest state has left thousands dead and more than one million homeless.
US Secretary of State John Kerry said the deal “could mark a breakthrough for the future of South Sudan”.
“The hard journey on a long road begins now and the work must continue,” added Mr Kerry, who had played an instrumental role in bringing together the two sides in the conflict.
“I saw with my own eyes last week the stakes and the struggles in a new nation we helped courageous people create. The people of South Sudan have suffered too much for far too long,”
The UN has accused both the South Sudanese government and the rebels of crimes against humanity, including mass killings and gang-rape.
The rivals signed the deal in the Ethiopian capital, Addis Ababa late on Friday, after their first face-to-face meeting since the hostilities began.
Mr Kiir and Mr Machar are to issue immediate orders for troops to end combat and to allow in humanitarian aid.
It was not immediately clear who would form the transitional administration.
Adapted From BBC