ADDIS ABABA, Ethiopia (AP) — The African Union Saturday joined regional and international organizations in threatening South Sudan's warring factions with sanctions.

Sanctions will be imposed on all parties in South Sudan who continue to undermine the cessation of hostilities agreement, the African Union Peace and Security Council said.

The council urged the government and rebels to establish the structure for a transitional government of national unity before the end of the African Union summit in Addis Ababa, which concludes Saturday.

The U.N. Security Council and IGAD have also threatened sanctions on those hindering the peace process.

Fighting broke out December 2013 between President Salva Kiir's troops and those loyal to former vice president Riek Machar.

Kiir and Machar have met at least twice this week to hold negotiations.

The two sides have signed several peace deals brokered by neighboring governments, but none have stopped the warfare.

Much of the violence has pitted the Dinkas, who back Kiir, against the Nuer, who support Machar.