The two men signed a pact a year ago to end a civil war that killed hundreds of thousands of people, displaced one-third of the population, and wrecked the economy.
Machar’s rare visit to the capital Juba – the first this year – comes before a November deadline to form a power-sharing administration, a key part of the deal agreed on by the rivals to end the ruinous conflict.
“The parties agreed to establish the government in time. When I said ‘in time’ it means on the 12th of November,” Information Minister Michael Makuei told journalists after Kiir and Machar met over three days.
The implementation of the accord had been delayed by several disputes. A key provision of the peace deal was the integration of former rebels into the army, which has still not occurred.
“I told you earlier on that talks between us are going well, and we will reach a deal soon,” Kiir said after the meeting, exchanging handshakes with Machar.
South Sudan became the world’s newest country in 2011 when it split from Sudan after decades of civil war. However, two years later it plunged into conflict after Kiir accused Machar, whom he had previously sacked from his post as vice president, of plotting a coup against him.
Machar is seeking assurances about his personal security before permanently returning to Juba, which he fled under a hail of gunfire when a previous peace deal collapsed in July 2016.
He returned in October 2018 for less than a day to celebrate the signing of the peace deal.
“Juba is home and I have come back to Juba. Even if I go away [again] for some time … we have made important progress,” Machar said.
Machar said he will visit the capital more often. “There will be frequent meetings,” he said, standing next to Kiir.
Observers say a political deal between the rivals is the only way to move forward with the 2018 peace agreement, which reached a stalemate on key issues of security and internal state boundaries.
Machar’s deputy, Henry Odwar, told journalists the leaders also discussed efforts to mediate with rebel groups not party to the peace deal that have continued fighting in different parts of the country.
A ceasefire is generally considered to have held – outside of the Central Equatoria region where holdouts have been fighting. However, the International Committee of the Red Cross said on Wednesday violence remained pervasive.
The aid organisation said in a statement it continues “to treat a large number of patients with gunshot wounds”.
The fighting in South Sudan has killed about 380,000 people and forced more than four million – almost one-third of the population – to flee their homes.
The World Food Programme said on Wednesday there was a slight improvement in food security as a result of the peace deal, however, “more than half the population of South Sudan – some 6.35 million people – do not know where their next meal will come from”.