South African former President Nelson Mandela, who has been hospitalized for the past two months with a serious lung infection, is increasingly alert and now able to "sit up" on his own, his youngest daughter told South African state broadcaster SABC.

Zindzi Mandela said her 95-year-old father, who remains in critical condition even though his health has recently improved, was becoming more "responsive" every day.

"He's fine. Tata (the Xhosa word for father) now manages to sit up, like now he sits up in a chair for a few minutes in a day, every day you know he becomes more alert and responsive," SABC quoted her as saying Friday on its Web site.

"Tata is determined not to go anywhere anytime soon, I cannot stress this enough. People must stop saying to the family 'let go let go,' we are just looking at this man who is saying 'I'm not going anywhere,'" Zindzi said.

"You know he just doesn't have the strength of a man, he just has the strength that is beyond anything that can be explained. Because even now with the challenges to his health, he somehow manages to bounce back when everyone assumes this is the end," she was quoted as saying.

Mandela's prognosis was lowered from "serious but stable" to "critical" on June 23.

The icon of the struggle against South Africa's former apartheid regime turned 95 in the hospital on July 18, receiving tributes and congratulations that day from hundreds of thousands of South Africans and leaders and well-wishers from around the world.

Mandela's lung problems are a legacy of the tuberculosis he contracted during the 27 years he spent in prison for his opposition to racial segragation.

After his release in 1990, Mandela and the last president of apartheid-era South Africa, F.W. de Klerk, led the process of peacefully dismantling that racist system.

They jointly received the Nobel Peace Prize in 1993 for their collaboration in that effort.

Elected president in 1994, Mandela's leadership was credited with helping to avert widespread racial violence in post-apartheid South Africa. EFE