President Barack Obama met privately Saturday with relatives of critically ill anti-apartheid leader Nelson Mandela in the midst of a three-nation tour through Africa.
Obama praised the former South African president as a towering historical figure who paved the way to social justice and racial reconciliation in a nation turn asunder by generations of white-minority rule.
"I also reaffirmed the profound impact that his legacy has had in building a free South Africa, and in inspiring people around the world -- including me," Obama said in a statement.
Obama also spoke by telephone with Graça Machel, Mandela's wife, while she remained at the 94-year-old former statesman's beside.
"I expressed my hope that Madiba draws peace and comfort from the time that he is spending with loved ones, and also expressed my heartfelt support for the entire family as they work through this difficult time," Obama said, referring to Mandela by his honorary clan name.
The White House announced earlier that Obama, "out of deference to Nelson Mandela's peace and comfort and the family's wishes," would not visit the Pretoria hospital where the ailing leader has spent three weeks being treated for a lung infection.
Meanwhile, police officials fired off stun grenades Saturday to break up a group of about 200 protesters who had congregated outside the Soweto campus of the University of Johannesburg, where Obama spoke at a town hall meeting with students. Some demonstrators carried signs depicting Obama with an Adolf Hitler mustache.
54-year-old Ramasimong Tsokolibane told the Associated Press that a host of trade unions and civil society groups protesting outside the university object to Obama's conduct as commander in chief.
"People died in Libya. People are still dying in Syria," Tsokolibane told the AP. "In Egypt, in Afghanistan, in Pakistan, drones are still killing people. So that's why we are calling him a Hitler. He's a killer."
A June Pew poll found that Obama enjoys widespread popularity among the South African people.
Obama earlier Saturday conducted bilateral talks with South African President Jacob Zuma at the historic Union Buildings. The two leaders held a press conference that touched on a wide range of political issues, from global trade to U.S. immigration reform.
But the focal point of the conference was Mandela's failing health and powerful legacy.
Zuma told assembled reporters that Mandela was in critical but stable condition Saturday, according to the Associated Press.
Obama called on African leaders and political actors across the globe to follow in Mandela's footsteps and put patriotism ahead of personal concerns.
“We as leaders occupy these spaces temporarily and we don’t get so deluded that we think the fate of our country doesn’t depend on how long we stay in office,” Obama said.
Obama honored Mandela again at an official dinner, toasting the iconic leader.
"I propose a toast, to a man who has always been a master of his fate, who taught who that we could be the master of ours, to a proud nation and South Africa's unconquerable soul," he said.
Obama is slated Sunday to visit Robben Island, the former penal colony where South Africa's first black president spent 18 of the 27 years he was locked up in apartheid jails, Reuters reported. He is due to head to Tanzania on Monday.
The Associated Press and Reuters contributed to this report.