South Sudan's government has agreed at a meeting of East African leaders to end hostilities against rebels accused of trying to overthrow the young country's regime, but the ceasefire was quickly thrown into doubt because the head of the rebellion was not invited.
An army spokesman suggested the fighting could go on despite the announcement by politicians in a faraway capital.
At the meeting in Kenya, South Sudan agreed not to carry out a planned offensive to recapture Bentiu, the capital of oil-producing Unity state, which is controlled by troops loyal to Riek Machar, the former vice president vilified by the government as a corrupt coup plotter.
"We are not moving on Bentiu as long as the rebel forces abide by the ceasefire," said Michael Makuei Lueth, South Sudan's information minister.
But no one representing Mr Machar was at the Nairobi meeting - a move possibly meant to deny him any elevated status that could also slow the search for peace.
In the field, the military reported no immediate changes in the battle for control of the world's newest country.
Army spokesman Philip Aguer said: "We have not seen any sign of a ceasefire. There is no ceasefire agreed by the two sides," an indication the planned assault on Bentiu could still take place.
Elsewhere, the country's military advanced on the rebel-held town of Malakal and had taken control of it by noon, Mr Aguer said.
Violence erupted on December 15 in South Sudan's capital Juba and quickly spread across the country. Ethnic Nuers - the group Mr Machar is from - say they are being targeted by Dinkas, the ethnic group of President Salva Kiir.
The UN, the South Sudan government and other analysts say the dispute is political at its heart, but has since taken on ethnic overtones.
The 25,000 people - mostly Nuers - sheltering at UN camps in Juba fear they would be targeted for death if they leave. Members of the government insist Juba's streets are safe for all.
The fighting has displaced more than 120,000 people and killed more than 1,000.
East African leaders meeting under a bloc called IGAD said in a statement that they "welcomed the commitment" by the South Sudanese government to cease hostilities. The leaders also condemned "all unconstitutional action" to try to topple the government in Juba.
The joint statement urged Mr Machar to make similar commitments to stop fighting. Indeed, the bloc laid bare how one-sided the talks have been so far as it directed its council of ministers to "make contact" with Mr Machar.
The statement said face-to-face talks between the two sides should happen by Tuesday.
In Juba's corridors of power, disdain for Mr Machar is strong. Mr Lueth said the former vice president is "on his way to hell if he's not careful" and that he could be executed by firing squad after a military trial.
South Sudan's government also says it will not release any of Mr Machar's imprisoned compatriots, a condition Mr Machar has set for his presence at the negotiating table.
Mr Lueth said that no Machar representatives belonged at the table of power in Nairobi.
"Is it a place for rebels? It would be a wrong approach to do it that way. This idea of trying to equate Machar with the government is not acceptable," he said.