A Kiir spokesman, Ateny Wek Ateny, has said "anything that brings peace in South Sudan is wanted." Machar fled South Sudan after new fighting erupted in the capital in July 2016, ending a brief attempt at peace in which he returned to his role as Kiir's deputy. He later was put under house arrest in South Africa, whose presidency on Wednesday welcomed Machar's participation in the talks.
The meeting will be mediated by the East African regional bloc that has led several rounds of failed peace talks. The Intergovernmental Authority on Development last month called for a meeting of Kiir and Machar ahead of an African Union summit on July 1 in Mauritania, saying it would inform a "final decision" on Machar's participation in the peace process.
Both sides in South Sudan's civil war have been accused of widespread abuses such as gang rapes against civilians, including along ethnic lines. A number of South Sudan officials have been accused by human rights groups of profiting from the conflict and blocking the path to peace.
Early this month the U.N. Security Council adopted a United States-sponsored resolution that threatens an arms embargo on South Sudan and sanctions against six people, including the country's defense chief, if fighting doesn't stop and a political agreement reached. The resolution asks Secretary-General Antonio Guterres to report to the council on that by June 30.
Regional bloc IGAD also has threatened to submit "punitive measures" against violators of December's failed cease-fire in South Sudan, though sanctions would need approval by the bloc's heads of state and government.
Associated Press writer Sam Mednick in Juba, South Sudan contributed.
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