South Sudanese President Salva Kiir has appointed Mr Nhial Deng Nhial as new Foreign Affairs minister.
The President made the announcement in a live broadcast on state television in Juba on Tuesday night.
The appointment seals the fate of Mr Deng Alor Kuol, who previously held the position.
Mr Alor has been in exile since March, having alleged a plot by South Sudanese president to kill him.
He is a member of former political detainees and was appointed to the Foreign ministry role under the terms of the 2015 August peace agreement.
Mr Nhial Deng is President Kiir's chief negotiator in the ongoing talks between rebels and government.