Anti-apartheid icon Nelson Mandela remains in critical condition in a Pretoria hospital, with U.S. President Barack Obama set to arrive in South Africa.
Mandela, who is suffering from a lung infection, has been described as in "critical but stable" condition.
While Obama regards the former antisegregation campaigner and longtime political prisoner as a "personal hero," the White House stressed that the U.S. president would respect "whatever the Mandela family deems appropriate" regarding a possible visit.
Using the clan name by which many South Africans refer to the 94-year-old Nobel Peace laureate, Obama said ahead of his visit, "I've had the privilege of meeting Madiba and speaking to him. And he's a personal hero, but I don't think I'm unique in that regard."
He added: "If and when he passes from this place, one thing I think we'll all know is that his legacy is one that will linger on throughout the ages."
Obama, who is on the second leg of a three-country Africa tour, has no public events scheduled after his arrival late on June 28, leaving open the possibility of a visit with Mandela.
Mandela spent 27 years in jail for convictions related to his struggle against apartheid.
He was awarded the Nobel Peace Prize in 1993 along with South African President Frederik Willem de Klerk, who oversaw the end of more than four decades of the legislated segregation known as apartheid.
Mandela went on to become South Africa's first black president, serving from 1994-99.
Based on reporting by Reuters, AFP, and dpa