He replaced the country's health minister Zweli Mkhize, widely respected for his handling of the coronavirus pandemic, but who is shrouded in an alleged corruption scandal involving coronavirus communications funding.

In a televised speech, Ramaphosa said Mkhize had asked to "step down...in order to bring certainty and stability to this important portfolio" and was replaced by Joe Phaahla, who until now was the deputy health minister.

Mkhize, 65, was placed on special leave early in June after graft investigators opened a probe into a 150 million rand ($10,4 million) health ministry communications contract.

Mkhize, who had been health minister since 2018, has denied any involvement with the Digital Vibes contract.

Ramaphosa made changes in 10 ministries, also removing the defence and security ministers, just weeks after the country was gripped by unprecedented unrest that broke out following the jailing last month of his predecessor Jacob Zuma.

He said the cabinet changes were necessary as the country "is facing several challenges".