Former president Nelson Mandela will be spending Christmas Day in hospital, the presidency said on Monday.
Spokesman Mac Maharaj said they received confirmation of this from his doctors.
President Jacob Zuma sent messages of well-wishes to the Mandela family and urged South African to keep him in their prayers.
“We urge all South Africans to keep Tata uppermost in their thoughts at every place of worship or entertainment tomorrow on Christmas Day, and throughout the festive season," said Zuma.
"We also humbly invite all freedom loving people around the world to pray for him. He is an ardent fighter and will recover from this episode with all our support."
The former statesman was said to be responding well to treatment as his stay in a Pretoria hospital extended into its third week.
He was originally flown to a hospital in Pretoria from his Eastern Cape home at Qunu on December 8. He was diagnosed with a lung infection and also underwent gallstone surgery.
His current stay in hospital is his longest since he was freed over two decades ago.
Mandela has a history of lung problems having suffered from tuberculosis towards the end of the 27 years he spent in prison.
Zuma paid a visit to Mandela on Saturday and again urged the nation to keep praying for the global icon.