Mandela's wife, Graca Machel, said yesterday that she is less anxious because the 94-year-old anti-apartheid leader and former South African president is responding to treatment.
Mandela was admitted June 8 to the hospital for a recurring lung infection.
People in South Africa and around the world have expressed concern for Mandela, sending messages of support for a man seen as a global symbol of reconciliation.
Mandela turns 95 on July 18, when commemorations will be held in his honour.
Mandela spent 27 years in prison during white rule and was released in 1990. He led the shift from apartheid to democracy and became president in all-race elections in 1994.