South Sudanese President Salva Kiir has declared a state of emergency in two states. Kiir on Wednesday declared the emergency in Unity and Jonglei states. The two regions's capitals are now controlled by rebel forces loyal to former Vice President Riek Machar, who Kiir has accused of plotting a coup.
The rebel delegation earlier arrived in the Ethiopian capital Addis Ababa. They said government negotiators had not yet arrived. Both sides have agreed in principle to a ceasefire but neither has indicated when the fighting would stop.
Mediators are concerned that fighting around the flashpoint town of Bor could spoil the talks even before they begin.
A South Sudan army soldier stands next to a machine gun mounted on a truck in Malakal town,
497km (308 miles) northeast of capital Juba, December 30, 2013 a few days after retaking the
town from rebel fighters.