Former South African President Nelson Mandela remains hospitalized after undergoing recent gallstone surgery and treatment for a lung infection.

A presidential spokesman said Monday that the public should assume that Mr. Mandela's health is improving unless it supplies information to the contrary.

The 94-year-old anti-apartheid leader was admitted to a Pretoria hospital on December 8. He underwent surgery for gallstones this past Saturday after being treated earlier for a lung infection.

Mr. Mandela, a Nobel Peace Prize laureate, became South Africa's first black president in 1994 after spending 27 years in prison for his opposition to apartheid.

He has grown frail and has made few public appearances in recent years.