South Africa's first black president Nelson Mandela is "responding better" to treatment in hospital, President Zuma says.Mr Zuma told parliament he was happy with the progress being made by Mr Mandela after a "difficult few days".The 94-year-old is spending his fifth day in a Pretoria hospital suffering from a recurrent lung infection.Mr Mandela's wife Graca Machel and other family members visited Mr Mandela on Wednesday.Mr Zuma noted that Wednesday was the 49th anniversary of Mr Mandela's being sentenced to life in prison under the apartheid regime."Our country is a much better place to live in now than it was before 1994 [when Mr Mandela was elected], even though we still have so much work to do," he said."We urge South Africans and the international community to continue to keep President Mandela and the medical team in their thoughts and prayers," he went on.On Tuesday Mr Zuma had described Mr Mandela's condition as "very serious but stabilised".Mr Zuma said the doctors were doing a "very good job", adding that the former president was a "good fighter".His ex-wife Winnie Madikizela-Mandela and other relatives visited the ailing former leader on Tuesday.Mr Mandela has been in intensive care since he was taken to hospital on Saturday for the third time this year.In December, he spent 18 days undergoing treatment for a lung infection and gallstones.Before being admitted to hospital, Mr Mandela had been ill for some days at his Johannesburg home, with a recurrence of his long-standing lung problems, said a statement from the president's office on Tuesday.He was taken to hospital when his condition worsened at 01:30 on Saturday (23:30 GMT Friday).Widely referred to by his clan name Madiba, Nelson Mandela served as president from 1994 to 1999.He was previously imprisoned for 27 years, and is believed to have suffered damage to his lungs while working in a prison quarry.He contracted tuberculosis in the 1980s while being held in jail on the windswept Robben Island.He retired from public life in 2004 and has been rarely seen at official events since.