JOHANNESBURG, South Africa (AP) — Anti-apartheid leader Nelson Mandela could spend a few more days in the hospital for care, South Africa’s president said Tuesday, as the 94-year-old spent an eleventh day under doctors’ care after suffering from a lung infection and undergoing surgery.

President Jacob Zuma said Mandela’s age meant the politician needed “extraordinary care” from medical professionals. However, he tried to assure a public increasingly worried about the health of a man many view as a living embodiment of the nation’s hopes after it abandoned white racist rule and became a full democracy.

Doctors “say there is no crisis, but add that they are in no hurry to send him home just yet until they are satisfied that he has made sufficient progress,” Zuma said in a statement issued by his office. “We urge the public to continue supporting (Mandela), but at the same time to understand that he is 94 years old and needs extraordinary care. If he spends more days in hospital, it is because that necessary care is being provided.”

The statement also said presidential spokesman Mac Maharaj visited Mandela on Tuesday, who immediately asked: “Mac, what are you doing here?”

Tuesday marked Mandela’s eleventh day in hospital. South Africa’s government has said the 94-year-old Mandela was admitted December 8 to a hospital in the country’s capital, Pretoria, initially for medical tests. It then said Mandela had a recurrent lung infection, a chronic problem as he contracted tuberculosis while in prison and had an acute respiratory infection in 2011.

On Saturday, the government said Mandela underwent endoscopic surgery to remove gallstones. That’s a procedure in which a patient usually receives sedatives and an anesthetic to allow a surgeon to put an endoscope down the throat, authorities say. The surgeon then removes the gallstones, which are small, crystal-like masses that can cause a person tremendous pain.

Mandela, a leader in the anti-apartheid liberation movement called the African National Congress, served 27 years in prison before being released. He later became the nation’s first democratically elected president in 1994 under the ANC’s banner. He served one five-year term before largely retiring from public life.

In the time since, Mandela has lived a private life, although he actively campaigned against HIV/AIDS. He last made a public appearance when his country hosted the 2010 World Cup soccer tournament. The Nobel laureate has also grown more frail in recent years, with his grip on politics in the nation ever slackening.