South African president Jacob Zuma says Nelson Mandela's health improved overnight, and his condition remains critical but is now stable.
He received the update from the medical team that is treating the 94-year-old anti-apartheid leader at a Pretoria hospital, the president's office said in a statement.
Mr Zuma, who visited Mr Mandela on Thursday, said the former president is "much better" than when he visited him on the previous night. Mr Zuma cancelled a visit to Mozambique.
His office says it is disturbed by what it calls rumours about Mr Mandela's health. Unconfirmed reports and speculation about Mandela have been swirling on social media and other forums.
Earlier one of his granddaughters, Ndileka Mandela, also said he was critical but stable as she and other family members stepped outside the Pretoria hospital to collect flowers and messages of support left outside the building.
She says it has been a difficult situation for the family, especially because they are coping with Mr Mandela's illness in the public eye.
One of Mr Mandela's daughters says he is in very critical condition but is still opening his eyes and reacting to touch. Makaziwe Mandela told South Africa's state broadcaster that he is still giving the family hope, even though "anything is imminent." She says her family will wait with him until "the time to go."
Members of a choir from the Salvation Army prayed and sung outside the hospital and members of the youth league of the country's ruling party, the African National Congress, were planning prayer meetings to honour Mr Mandela.
Mr Mandela was taken to hospital on June 8 with what the government said was a recurring lung infection.