South Sudanese rebel leader Riek Machar has arrived in Ethiopia for his first direct talks with South Sudan President Salva Kiir since fighting and ethnic violence erupted in December.
A reporter for VOA in Addis Ababa reports Machar entered the country on Thursday and is due to make his way to the capital later in the day.
The two men are set to meet Friday for peace talks mediated by the East African bloc IGAD. Negotiations between the rebel and government delegations have dragged on for several months with little progress.
President Kiir agreed to attend the talks with his former vice president after meeting with U.S. Secretary of State John Kerry in South Sudan last week.
Shortly after the visit, the U.S. announced its first sanctions related to the South Sudan conflict. The sanctions targeted a government and a rebel leader linked to violence that has left thousands of people dead since mid-December and displaced more than a million.
The unrest was sparked by a power dispute between President Kiir and Machar.
Also Thursday, Amnesty International said a new investigation into South Sudan's unrest shows both sides have committed "horrific atrocities" that constitute war crimes and crimes against humanity.
The rights group says its researchers saw a mass grave in the town of Bor that a government official said contained 530 bodies.
Researchers also say civilians have been "systematically targeted" in places of refuge.
Last month, the United Nations mission in South Sudan accused rebel fighters of massacring hundreds of civilians in the town of Bentiu. The rebels denied the allegation.