Conflict rages on despite ceasefire deal, leaving more than one million displaced and four million severely hungry.
South Sudan rebel chief Riek Machar will miss an international deadline on Saturday to return to the capital to take up the post of vice president, the government and rebels have said, with his arrival now expected next week.
“There is no coming today,” Minister of Information Michael Makuei said, adding that the government will issue flight clearance for Machar to arrive by plane from Ethiopia only after international monitors have verified the number of weapons carried by the rebels accompanying him.
The rebels, who were at an airport in Ethiopia, said they were ready to fly but needed permission to do so.
An AFP reporter at the airport in Gambela said there was growing frustration among the rebel troops, who have now been there for several days, waiting to leave.
UN chief Ban Ki-moon has urged Machar to return to Juba “without delay”, while the United States, Britain and Norway – key international backers of peace efforts – demanded he return by Saturday.
Machar was due to return to the capital Juba on April 18 to take up the post of first vice president alongside his archrival President Salva Kiir.
His failure to arrive has thrown an August 2015 peace agreement to end over two years of intense civil war into jeopardy.
Under intense international pressure, the two sides reached agreement on Friday on the number of troops protecting Machar and the exact number of weapons they can carry.
Machar can bring with him 195 men, carrying AK-47 assault rifles as well as 20 machineguns and 20 rocket-propelled grenades.
Rebel spokesman James Gadet, however, said the weapons had already been checked by Ethiopian officials, and could also be verified upon their arrival in Juba.
In a statement released earlier this week, Festus Mogae, JMEC chairman, said: “No further delay is tolerable.”
Since December 2013, the government and opposition have been engaged in a brutal conflict that has killed more than 50,000 and displaced more than two million people.
Both sides of the conflict have been accused of committing war crimes.