Zuma visited Mandela Saturday at the Pretoria hospital where he is being treated, the South African Broadcasting Corp. reported.
Presidential spokesperson Mac Maharaj said: "President Zuma assured him of the love and support of all South Africans, young and old, and the whole world. We urge South Africans to continue praying for our beloved Madiba during this period. Our hearts are with the whole family and relatives."
"Madiba" is Mandela's clan name, meaning "father."
Mandela was first admitted to the hospital two weeks ago for treatment of a recurring lung infection. He later underwent a procedure to remove gallstones.
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