"I visited him yesterday and he was watching television with headphones," said Zindzi Mandela in an interview with Britain's Sky TV. "He gave us a huge smile and raised his hand ... He responds with his eyes and his hands."
Mandela is gaining "energy and strength," said his daughter. "I should think he will be going home anytime soon."
The latest description by Zindzi - who is one of Mandela's daughters by his second wife, Winnie Madikizela-Mandela - is a significant improvement from court documents filed by the family earlier this month which said he was on life support and near death.
Mandela has been in a Pretoria hospital since June 8 and officials say his condition is critical but stable.
The news of the improvement in Mandela's health will boost his supporters in South Africa and around the world who are preparing to celebrate his 95th birthday on Thursday, a day declared by the United Nations as a way to recognize the Nobel Prize winner's contribution to reconciliation.
Interest in Nelson Mandela International Day has ignited as a result of the former South African president's hospitalization in Pretoria and people find ways to honor his ideals.
A Johannesburg-based foundation named after Mandela and numerous other groups have asked people to volunteer 67 minutes to charity to match what they say are the 67 years that Mandela served his community. Mandela led South Africa through a tense transition from apartheid to democracy and became president in the country's first all-race elections in 1994.
President Jacob Zuma will mark the birthday by overseeing the donation of houses to poor white families in the Pretoria area, in line with his Cabinet's theme to commemorate Mandela's birthday this year by focusing on food security, shelter and literacy.
In Cape Town, labor activists are holding an event at St. George's Cathedral on Thursday, in remembrance of Mandela's years of service and to encourage people to donate food to charity while leaving messages of support for the former leader's family.
Mandela, who is in critical but stable condition, has been hospitalized since June 8, and hundreds of well-wishers have left prayers and messages of hope at his Johannesburg home and at the hospital where he is being treated. Legal documents have said Mandela's breathing is machine-assisted.
The anti-apartheid leader has also inspired artists and graphic designers who celebrate his life through paintings and posters.
A group of young South African designers created a poster project to offer a global perspective of Mandela with submissions from around the world. The group whittled down 700 posters submitted by designers from more than 70 countries, to 95 for each day of Mandela's life.
The posters will be unveiled Wednesday and a single special edition auctioned off to raise money for a proposed children's hospital that will be named after Mandela, the group said.
"He carries across this concept of humanity and selflessness," said Mohammed Jogie, co-founder of the project.
South African artists John Adams and Paul Blomkamp have painted two of the largest Mandela paintings to honor the man who spent 27 years imprisoned during the system of white minority rule known as apartheid.
Blomkamp said his painting was inspired by Mandela's energy, which he described as exceptional. Blomkamp said an image of his painting will be featured in a display in New York's Times Square Thursday in honor of Mandela's birthday.