"Mandela enjoyed a full breakfast this morning, and the doctor reported that he is making steady progress," Xinhua quoted a statement from the presidency as stating and adding that he "remains under the treatment and observation".
The 94-year-old was admitted to hospital just before Wednesday midnight due to recurrence of his lung infection.
Mandela has a history of lung problems after suffering from tuberculosis towards the end of his 27-year term for national liberation movement. He became the first democratically-elected president of South Africa in 1994 following the end of apartheid.
Early this month, Mandela was admitted to a Pretoria hospital for a scheduled check-up after the long standing abdominal complaint. He was discharged the following day.