0500 GMT April 19, 2019
Machar had fled to the Democratic Republic of Congo after fresh wave of fighting erupted last month between his forces and government troops in Juba. On August 23, Khartoum declared that Machar had arrived in Sudan for "medical treatment."
"He has been discharged," said Manasseh Zindo, a senior aide from Machar's party, known as the SPLM/A (IO).
"His condition has improved. His leg has improved. Basically, what we know is that his leg had swollen due to long-distance walking," Zindo said Friday.
Sabiet Majok, another party aide, said the rebel leader had left the hospital on Friday morning.
"He's in good health now, but he will stay in Khartoum for some more days," he added.
Majok also said Machar will meet President Omar al-Bashir during his stay in Sudan.
He further said Machar planned to visit Ethiopia, Djibouti, Uganda and Kenya, the other member states apart from Sudan of the Intergovernmental Authority on Development (IGAD).
In late July, Machar said he would not return to his country before the deployment of regional troops to Juba.
South Sudan’s government rejected a proposal submitted by the US for the UN Security Council to send 4,000 additional peacekeeping troops to the African country.
South Sudan has witnessed a new wave of conflict since July 8, when gunfire erupted near the state house in Juba, where President Salva Kiir and then Vice President Riek Machar were meeting for talks. More than 300 people have been killed in the clashes.
The country gained independence from Sudan in 2011. It has gone through turmoil ever since.
The conflict in South Sudan has exposed deep ethnic divisions. It erupted after a power struggle between President Kiir, a member of the Dinka ethnic group, and rebel leader Machar, a member of the Nuer ethnic group.
Relations between Khartoum and Juba have been strained amid claims that Sudan supports the rebels in the civil war in South Sudan.