South Sudan's government announced on Saturday that it would continue pursuing peace talks to end a 20-month civil ar, but without the participation of President Salva Kiir, according to his spokesman.
"We are still engaging in the peace efforts, that has not stopped," Presidential spokesman Ateny Wek Ateny told AFP, a day after government officials had said talks in Ethiopia would be suspended.
The government and rebels are under intense international pressure to strike a deal before an August 17 deadline or risk possible sanctions.
Tens of thousands of people have been killed in a war marked by widespread atrocities on both sides, and diplomats have warned any failure to sign a peace deal could trigger "serious consequences" for the rival leaders.
Mediators had expected Kiir to travel to Addis Ababa before the Monday deadline to meet with rebel chief Riek Machar and sign a possible deal.
But Ateny said that instead, Vice-President James Wani Igga would go in his place.
"It has been decided the president should not be the one travelling," Ateny said, without giving details of when he may leave for the talks.
South Sudan's civil war began in December 2013 when Kiir accused his former deputy Machar of planning a coup, setting off a cycle of retaliatory killings that has split the poverty-stricken, landlocked country along ethnic lines.
Regional mediators, backed by US President Barack Obama during his recent visit to Ethiopia, had given Kiir and Machar until August 17 to halt the civil war.
On Tuesday however, top rebel generals said they had split from Machar, accusing him of seeking power for himself, and adding they would not recognise any deal agreed.
The latest round of talks opened on August 6, mediated by the regional eight-nation bloc IGAD, the Intergovernmental Authority on Development, as well as the United Nations, African Union, China and the "troika" of Britain, Norway and the United States.
Ateny said mediators "should take into the consideration the split between the rebels" to allow the government to determine who was in control in rebel zones.
"Since the reason for peace is to silence the guns, then we need all those with the guns to take part," Ateny added.
"It is not about the political deals, but about engaging the field commanders on the ground."
The war has been characterised by ethnic massacres and rape. Recent attacks have included castration, burning people alive and tying children together before slitting their throats.