(COMBO) This combination of pictures created on June 19, 2018 shows (L)South Sudan's President Salva Kiir arriving to attend the Ordinary Session of the Assembly of Heads of State and Government of the African Union (AU) during the 30th annual AU summit in Addis Ababa on January 29, 2018 and (R) South Sudan's rebel leader Riek Machar gestures as he holds a press conference in Kampala on January 26, 2016.
 South Sudan president Salva Kiir will meet with rebel leader Riek Machar in Ethiopia's capital on June 20, 2018, their first meeting in nearly two years, an Ethiopian official said on June 19, 2018.
 / AFP / SIMON MAINA AND ISAAC KASAMANI
South Sudan's President Salva Kiir, left, and his former vice president Riek Machar. AFP

South Sudan negotiators in race to save peace deal