South Sudan's warring factions have opened peace talks in Ethiopia, as violence continues in at least two regions of South Sudan.
The two sides begin face-to-face negotiations in Addis Ababa Sunday following days of delays.
Representatives for President Salva Kiir and ex-vice president Riek Machar took part Saturday in opening ceremonies for talks.
U.S. State Department deputy spokesperson Marie Harf says the talks are "of critical importance" to the people of South Sudan.
Ethiopian Foreign Ministry spokesman Dina Mufti - in an interview with VOA - says several items will be high on the agenda.
"Definitely cease-fire will be on the top of agenda, then the issue of opening humanitarian corridors, the issue of releasing detainees and other issues."
Mufti says negotiators are anxious to find a resolution to the fighting, which has left more than 1,000 people dead.
"All sides are feeling the need, the urgency, for a cease-fire and everything else."
South Sudan's unrest began in mid-December, when renegade soldiers attacked an army headquarters. President Kiir accused Machar of a coup attempt.
On Saturday, there were reports of heavy fighting near Bor, the rebel-held capital of Jonglei state. Government troops have launched an effort to reclaim the city. And explosions and automatic artillery fire rattled a government district in the capital, Juba, on Saturday.
The talks in Ethiopia are being mediated by the East African regional bloc IGAD (Intergovernmental Authority on Development).
EU Horn of Africa representative Alexander Rondos is at the meeting. He says the responsibility to find a solution to the conflict rests in the hands of South Sudan's political leadership.
"The leadership of South Sudan, the entire political leadership needs to find a resolution, there are no alibis, only they can find that solution. And they must do everything to help the negotiators from IGAD (Intergovernmental Authority on Development) to find that solution and very quickly."
Machar told VOA Wednesday that President Kiir is responsible for much of the unrest. He said peace cannot be achieved under the president's leadership.
Witnesses say some of the violence is ethnically motivated, with supporters of Mr. Kiir, a member of the Dinka tribe, and supporters of Machar, from the Nuer tribe, targeting each other.