A delegation from the Juba government, led by Albino Mathem, the country’s presidential envoy, arrived in Nairobi on Tuesday, ahead of the scheduled talks.
It comes as South Sudan prepares for its first post-independence elections scheduled for December this year, but uncertainty looms over whether the election will take place.
President William Ruto in late March appointed Sumbeiywo as the Chief Mediator for the South Sudan mediation peace process.
Ramaphosa met with key South Sudanese actors, including President Salva Kiir, and his first deputy Riek Machar, to receive updates on the peace agreements implementation.
The United Nations reports that South Sudan will hold general elections in December 2024, signalling the conclusion of a transitional period that followed a bloody civil war.