Zuma, who arrived at the Medi-Clinic Heart Hospital in Pretoria on Thursday, had been due to attend a summit in Maputo of the Southern African Development Community (SADC) to discuss regional infrastructure, but pulled out after visiting the 94-year-old former president in hospital late on Wednesday.
“Over the past 48 hours, the condition of former president Madiba has gone down,” presidential spokesperson Mac Maharaj told SABC.
On Thursday morning, Mandela’s eldest daughter Makaziwe led a group of his grandchildren to see him in the Pretoria hospital where he has been receiving treatment since 8 June for a lung infection.
Makaziwe told SABC radio after her visit that Mandela was responding to touch.
“I won’t lie, it doesn’t look good. But as I say, if we speak to him, he responds and tries to open his eyes. He’s still there. He might be waning off, but he’s still there,” she said.
One granddaughter, Ndileka, described him as “stable” and thanked well-wishers from around the world for their support.
Maharaj had earlier declined to comment on media reports that Mandela was on life support, saying his privacy should be respected.
Mandela’s fourth hospitalisation in six months has forced a growing realisation among South Africans that the man regarded as the father of their post-apartheid “Rainbow Nation” will not be among them forever.
“Mandela is very old and at that age, life is not good. I just pray that God takes him this time. He must go. He must rest,” said Ida Mashego, a 60-year-old office cleaner in Johannesburg’s Sandton financial district.
‘Celebrating his life’
US President Barack Obama is due to visit South Africa at the weekend as part of a three-nation Africa tour he has already started in Senegal.
Maharaj said it was too early to say whether Obama’s schedule in Johannesburg and Cape Town on Saturday and Sunday might be affected by Mandela’s worsening condition.
Well-wishers’ messages, bouquets and stuffed animals have piled up outside Mandela’s Johannesburg home and the wall of the hospital compound where he is being treated in the capital.
As they headed to work on Thursday, South Africans seemed resigned to the prospect of losing their hero.
“We are all going to feel bad when he passes, but at the same time we will be celebrating his life. He has done so many great things for this country,” said John Ndlovu, a 25-year-old office worker.
Mandela stepped down in 1999 after one five-year term in office.
Since then he has played little role in public life, dividing his time in retirement between his home in the wealthy Johannesburg suburb of Houghton and Qunu, the village in the impoverished Eastern Cape province where he was born.
The public’s last glimpse of him was a brief clip aired by state television in April during a visit to his home by Zuma and other officials from the ANC.
At the time, the ANC said Mandela was “in good shape”, although the footage showed a thin and frail old man sitting expressionless in an armchair.