South African President Cyril Ramaphosa will announce changes to his cabinet at 19:00 (17:00 GMT) on Monday, his spokesperson Vincent Magwenya said on Sunday.
The changes were widely expected after Mr Ramaphosa was re-elected as leader of the ruling African National Congress (ANC) party in December.
It paved the way for him to seek a second presidential term in elections scheduled for next year.
Mr Ramaphosa is expected to name a new deputy president following the resignation of David Mabuza.
The seat is widely expected to be taken by the new ANC Deputy President Paul Mashatile.
Mr Ramaphosa is also expected to fill the newly created position of electricity minister as the country battles a power crisis.