In a decree read out on the state-owned South Sudan Broadcasting Corporation (SSBC) on Friday, Kiir dismissed Tiop Monyluak and re-appointed Stefano Wieu as the replacement.
Wieu had been dismissed from the same position in May of last year. Monyluak was appointed to the position when Kiir removed Wieu.
The president did not give reasons for the replacement. However, it follows an attack on Monday by heavily armed youth from Mayom County in neighboring Unity State on Abiemnom County headquarters in Ruweng, which resulted in the deaths of at least 27 people, including two women and a child.