US President Barack Obama flies to South Africa on Friday to pay homage to his hero Nelson Mandela, who is fighting for his life in hospital.
Mandela’s ill health means the two men, who shattered racial boundaries on either side of the Atlantic, will not hold a long-anticipated meeting for the cameras.
But reflections on Mandela’s extraordinary journey from prisoner to president will permeate Obama's three-day stay.
Mandela, who turns 95 next month, was rushed to hospital three weeks ago with a recurrent lung disease.
On the eve of Obama’s visit, South Africa’s first black president was said to be in a critical condition, but had stabilised since a scare forced his successor Jacob Zuma to cancel a trip to neighbouring Mozambique.
“He is much better today,” said Zuma after seeing Mandela on Thursday for the second time in less than 24 hours.
Yet South Africans, including Mandela’s family, braced for the worst.
“I won't lie. It doesn’t look good,” daughter Makaziwe Mandela said. But “if we speak to him he responds and tries to open his eyes – he’s still there.”
Obama, the United States’s first black president, led a chorus of support for the man he called a “hero for the world.”
Mandela’s plight has lent a deeply poignant tone to the visit, around which Obama has built a three-nation Africa tour, and his plans could yet be disrupted by sudden developments in the ex-president’s condition.
The White House says it will defer to the Mandela family and the South African authorities on any aspect of the visit that kicks off on Friday evening when Obama arrives.
A visit by Obama to Mandela’s former jail cell on Robben Island, off Cape Town on Sunday would now take on extra “profundity,” he said.
Speaking in Senegal on the first leg of his long-awaited African trip, Obama described Mandela as “a personal hero.”
“I think he is a hero for the world, and if and when he passes from this place, one thing I think we all know is that his legacy is one that will linger on throughout the ages.”
The US president recalled how Mandela had inspired him to take up political activity, when he campaigned for the anti-apartheid movement as a student in the late 1970s.
The men met in 2005, when the former South African president was in Washington, and Obama was a newly elected senator, and the two have spoken several times since by telephone.
But there has been no face-to-face meeting between them since Obama was elected in 2008.
Meanwhile outside Mandela’s hospital a wall of messages and flowers has become the focal point for a nation saying a long goodbye to one of the greatest figures of the 20th century.
“I came to pray for our father Nelson Mandela. We are wishing for our father to be fine,” said Thabo Mahlangu, aged 12, part of a group from a home for abandoned kids who travelled to Pretoria.
Mandela has been hospitalised four times since December, mostly for a stubborn lung infection.