The sacked vice-president of South Sudan has left the country, weeks after deadly clashes between his troops and government forces in the capital.
A spokesperson said Riek Machar was in Democratic Republic of Congo's capital Kinshasa but that he wanted to travel on to Ethiopia.
According to the Associated Press news agency, the UN had indicated Mr Machar was in danger and had assisted him.
He initially fled the capital, Juba, during violence in July.
A UN spokesperson, Farhan Haq, said the UN had learned on Wednesday that Mr Machar was in DR Congo near the South Sudan border and decided to airlift him to Kinshasa.
The UN official said Mr Machar needed to be airlifted to safety and that he had been given medical assistance.
Mr Machar demanded a neutral force be deployed in July to keep peace and guarantee his safety after his bodyguards and President Salva Kiir's presidential guards fought each other, sparking days of violence.
Hundreds of people died and more than 100,000 fled across the border.
The fighting erupted less than a year after a peace deal was signed to form a unity government and end the civil war.
The UN has launched an independent investigation into allegations that its peacekeepers failed to respond when troops loyal to Mr Kiir attacked a residential compound popular with foreign aid workers last month.
During the attack, a local journalist was shot dead at point-blank range and troops reportedly raped several women, among them foreigners working for relief agencies.
More on South Sudan's crisis:
- The wounds of war in South Sudan
- Juba residents: 'We are counting the dead'
- Five obstacles to peace in South Sudan
- 'We want peace - and ice cream'
Political differences between Mr Machar and Mr Kiir ignited the civil war in December 2013 - and they only agreed to settle their differences under intense international pressure, signing a peace deal last August.
Mr Machar returned to Juba in April to take up the post of vice-president, but President Kiir dismissed him in the wake of the latest violence.
He has not been seen in public since and his exact whereabouts are unknown.
A member of his opposition SPLA-IO party told the BBC he was en route to Ethiopia, via the Democratic Republic of Congo, but earlier media reports said he was in Tanzania or Chad.
Mr Machar had been "safely evacuated to a safe country in the region" after a "botched attempt to assassinate" him, a statement from the SPLA-IO said.
Last week, the UN authorised a 4,000-strong African protection force for Juba with a more robust mandate than the 12,000 UN soldiers already in the country.
But South Sudan's government said it opposed the deployment and it is not clear how the mission can go ahead without its co-operation.