Nelson Mandela "continues to get better" after more than a week in hospital battling a lung infection although his condition remains serious, South African President Jacob Zuma said Sunday.

"As you are aware, president Nelson Mandela is still in hospital in Pretoria. We are grateful that he continues to get better," Zuma said at a public rally.

"Over the last two days, although he remains serious, his doctors have stated that his improvement has been sustained. He continues to engage with family."

The 94-year-old anti-apartheid hero and South Africa's first black president was admitted to a private Pretoria clinic in the early hours of June 8, his fourth hospitalization since December.

Several family members, including his wife Graca Machel and ex-wife Winnie Madikizela-Mandela have paid visits to his bedside.

Mandela has a long history of lung problems since being diagnosed with early-stage tuberculosis in 1988 during his 27 years in prison under the apartheid regime.

In December he underwent surgery to remove gallstones as he recovered from a lung infection. In March he was admitted for scheduled overnight checkup before returning to hospital later that month for 10 days, again for treatment for the lung infection. (AFP)