Following four days of tough negotiations, the East African bloc IGAD confirmed early Monday morning that progress had been made toward ending South Sudan's 13-month civil war.

IGAD's chief mediator, Seyoum Mesfin, said that the two leaders of the warring factions - South Sudanese President Salva Kiir (pictured right) and his former deputy-turned rebel leader Riek Machar (pictured left) - had signed a new ceasefire.

"Complete cessation of hostilities in South Sudan is expected as of [Monday morning]," Mesfin told reporters in the Ethiopian capital of Addis Ababa.

Kiir and Machar had also reached a partial power-sharing agreement, the details of which were not immediately made public.

The opponents are to resume talks on February 20, which "would be final and that would lead them into concluding a comprehensive agreement to end the crisis in South Sudan," Mesfin added.

Fighting broke out in South Sudan in December 2013, after Kiir accused his former deputy Machar of attempting a coup. Tens of thousands of people have died in the fighting, which has been interrupted several times by brief ceasefires.

In light of the two sides' inability to uphold previous promises to halt fighting, Mesfin said that South Sudan would face "tough measures" with the help of the United Nations Security Council and the African Union's Peace and Security Council if Kiir and Machar failed again.

kms/gsw (AP, AFP, Reuters)