President Jacob Zuma said Nelson Mandela is "responding very well to the treatment" as he urged the country not to panic.
He told BBC News: "Of course I have been saying to people, you should bear in mind Madiba is no longer that young and if he goes for check-ups every now and again, I don't think people must be alarmed about it. I would like to really say the country must not panic."
More top news
The Duke of Cambridge is to end his role as an air ambulance pilot and become a full-time Royal, Kensington Palace has announced.
The UN released the before and after images and described the damage, reportedly caused by Islamic State, as 'a new war crime'.
The 16-year-old's body was found on January 16 on a pathway in Dinnington, South Yorkshire.