"Out of deference to Nelson Mandela's peace and comfort and the family's wishes, [the president and first lady] will not be visiting the hospital," the White House said.
The president and first lady will, however, meet privately with members of the Mandela family "to offer their thoughts and prayers at this difficult time."
The president downplayed expectations Friday that he would meet face-to-face with Mandela during his stay in South Africa.
"I don't need a photo-op," the president told reporters. "The last thing I want to do is to be in any way obtrusive at a time when the family is concerned about Nelson Mandela's condition."
Obama and Mandela have met only once in person, during a spontaneous meeting in Washington in 2005, when Obama was just a junior Senator.
It was widely speculated that Obama would meet with Mandela for the first time as president during his week long trip to Africa, in what would have been a deeply symbolic face-to-face encounter.
The 94-year-old former president was admitted to the hospital three weeks ago for a chronic lung infection.