Nelson Mandela's daughter has said her father is "at peace with himself," as South Africa and the world follow updates on the former president's worsened health.
The 94-year-old Nobel peace laureate is said to be in a critical condition, brought on by long-running lung problems.
The presidential spokesman Mac Maharaj said that it was a “sombre time”.
And in an interview with American network CNN, Makaziwe Mandela said she believed her father was “at peace with himself.”
“He has given so much to the world. I believe he is at peace,” she said.
Asked if the family should “let him go”, she said they wouldn't because he had not asked them to.
Before becoming the country's first black president, Mandela first contracted tuberculosis during his stay in Robben Island prison. He is said to have damaged his lungs while working in a prison quarry.
President Jacob Zuma said doctors are doing everything possible to ensure Mandela's wellbeing and comfort during his fourth hospital visit since December. He refused to give any details about Mandela's condition, saying: “I'm not a doctor.”
He went on: “Madiba (Mandela's clan name) is critical in the hospital, and this is the father of democracy. This is the man who fought and sacrificed his life to stay in prison, the longest-serving prisoner in South Africa.
"He is one of those who has contributed to democracy.
“All of us in the country should accept the fact that Madiba is now old. As he ages, his health will ... trouble him and I think what we need to do as a country is to pray for him.”
Zuma, who in the past has given an overly sunny view of Mandela's health, briefly described his visit to the hospital in the capital and seeing Mandela.
“It was late, he was already asleep,” he said. “And we then had a bit of a discussion with the doctors as well as his wife, Graca Machel, and we left.”
Petunia Mafuyeka, a nurse, said as she headed to work in Johannesburg: “If it's his time to go, he can go. I wish God can look after him.
“We will miss him very much. He fought for us to give us freedom. We will remember him every day. When he goes I will cry.”