South Sudans rebel leader Riek Machar will miss an international deadline on Saturday to return to capital Juba as part of a peace deal between the government and the rebel group.
South Sudanese officials and rebels said, Machar's arrival in the capital is now expected to be next week.
"There is no coming today," the countrys Minister of Information Michael Makuei said.
He also added that an approval will be issued for Machar to arrive by plane from Ethiopia, but only after international monitors have verified the number of weapons carried by the rebels accompanying him.
The rebels, who are at an airport in Ethiopias Gambela region, said they are ready to go but need permission to fly to Juba.
United Nations Secretary-General Ban Ki-Moon has urged Machar to return to Juba "without delay," while US, Britain and Norway who are the key international backers of peace efforts, have also demanded Machar return to Juba by Saturday.
Machar was expected to return to Juba on April 18 to become the countrys vice president alongside his rival President Salva Kiir, as part of the peace deal.
Machar and Kiir agreed on a power sharing deal in August 2015, in order to end a two-year conflict which caused thousands of people to be killed and more than two million people to flee their homes.
On Friday, under international pressure, both sides agreed on the number of rebel fighters to protect Machar and number of weapons which rebels can carry as they arrive.
Machar can bring with him 195 men, carrying AK-47 assault rifles, also 20 machine guns and 20 rocket-propelled grenades.
Political crisis led to a deadly conflict in December 2013 after President Kiir fired Machar from vice presidency. The violence escalated due to ethnic differences between Kiirs dominant Dinka ethnic group against Machars Nuer tribe.
The conflict, which began nearly two years after world youngest country became independent from Sudan, caused economic crisis and left 11 million people in shortage of food.