South Sudan rebels said their commander Riek Machar would yet again fail to return on Monday to Juba as part of a floundering peace deal, this time blaming international donors.
Key international backers of the peace process are infuriated at the repeatedly delayed return, with the United States saying both sides have stalled the return of Machar, a step hoped to help end over two years of intense civil war.
Machar, who fled Juba when the war broke out in December 2013, is due to forge a unity government with his arch-rival, President Salva Kiir, returning to the post of vice-president he was sacked from months before the violence began.
He is currently at a rebel base near Ethiopia, and he would need to go across the border to fly to Juba from the nearest airport at Gambella, Ethiopia.
Rebel spokesman William Ezekiel told AFP Machar's security force -- 195 troops and the UN and US sanctioned chief of staff, Simon Gatwech Dual -- were still hoped to fly Monday.
Ezekiel blamed the delay on the cancelling of flights funded by donors, who have said they must organise their own return after multiple chartered planes sent to collect the rebels left empty.
"We hope we can organise an airplane and he (Machar) can fly on Tuesday," Ezekiel said. "The chief of staff and soldiers we hope will leave today."
The flight for the troops was being paid for by "good Samaritans", he said.
Tens of thousands of people have been killed and more than two million been driven from their homes in the conflict, which has reignited ethnic divisions and been characterised by gross human rights.
The United States, who along with Britain and Norway, a grouping known as the "Troika", have provided key funding to the peace process, said both sides needed to demonstrate they are "genuinely committed" to peace.
"Despite the best efforts by South Sudan's neighbours, the Troika, United Nations Mission in South Sudan, China, the African Union, the European Union and, most importantly, by South Sudanese advocating for peace, leaders on both sides have blocked progress," the US State Department said late Sunday.
The British embassy in Juba said in a statement that Machar's return was "vital" to create a unity government.
"It is now time for the parties to take over the primary responsibility of ensuring this return," the statement read.
People on the streets of Juba appeared deeply frustrated at another delay.
"None of them seem serious," said William Sebit, a motorbike taxi driver waiting in a long line at a filling station amid severe fuel shortages. "If today is the day they have to show they mean the agreement they signed, this doesn't look good."
"If we can fund a civil war, how is it possible that we can't charter two planes from Gambella to Juba?" asked Geoffrey Duke, a South Sudanese peace activist.