Nelson Mandela "drew his last breath and just rested", his ex-wife Winnie said Thursday in her first public comments on his death.

Winnie Madikizela-Mandela said she rushed to the former South African president's bedside for his final moments, in an interview with Britain's ITV television.

She said: "I went close to him and I noticed he was breathing really slowly. I was holding him trying to feel his temperature and he felt cold. Then he drew his last breath and just rested... He was gone."

Mandela's second wife said doctors had assured the family that the anti-apartheid icon was not in pain in his final days.

She said the sacrifices of their relationship through his 27 years in jail were worth it for a liberated South Africa and she would go through the same again "100 times more".

The 77-year-old said she was now the senior head of the family but had no plans to inherit his political position.

"I consider myself very blessed to have been there when he drew his last breath," she said.

"I had been there sitting next to him for over three and a half hours and all that time he was going. Then I realised that God was very kind to us. He had given us such a long time for us to say goodbye.

"I knew we had reached the end. You get this numb feeling. You don't react to that. I can't describe that kind of sorrow.

"Even though he was 95 and had done so much, there was so much that was still not done. I felt in his case he had completed his journey."

Mandela was receiving intensive care for a respiratory illness at his Johannesburg home after being discharged on September 1 following an 86-day stay in a Pretoria hospital.

In his final days, Mandela could not speak due to the tubes in his mouth.

"Tata had been in pain for so long he was actually described by his doctors as a medical miracle," Madikizela-Mandela said.

Mandela's third wife Graca Machel told her that when he was discharged, "the doctors were sceptical and... thought it wouldn't take longer than three days.

"But they assured us all the time he was not in pain, he had enough medication."

Madikizela-Mandela said the hardest moment of all was when the military came to remove his body.

She tried to close his mouth but the doctors told her they would do it.

"I even thought then, maybe there's still breath left, he isn't gone yet," she said.

"The whole thing was so official. It struck me then, he was gone and that was the last journey for him.

"That was very difficult to take. I couldn't contain myself."

Mandela married Winnie in 1958 and they had two daughters. They separated in 1992 and divorced four years later.

Describing herself as "the most senior in the family" by "traditional right", she said she had grown close to her "little sister" Machel.

She said she felt uplifted by the global outpouring of emotion over Mandela's death, and insisted South Africa could cope without him because the country was "not short of leadership at all" in the ruling African National Congress.

President Jacob Zuma, the ANC leader, was booed at the memorial service in Soweto's Soccer City stadium on Tuesday.

Madikizela-Mandela saw her ex-husband lying in state on Wednesday, which she said was "very painful".

"It's very hard for the family to even share him even in his death after sharing with the whole world and our whole country while he was alive. He's still not really just ours.

"His whole life belonged to the nation and to the world and that's how I will remember him. He never thought of himself at any stage. He gave up everything for his nation."