US President Barack Obama has praised Nelson Mandela as “an inspiration to the world” while visiting South Africa.
The US leader, who was speaking in Pretoria after talks with President Jacob Zuma, does not intend to visit the 94-year-old, who has been critically ill for nearly a week.
But he met the Mandela family in private and spoke by telephone to his wife, Graca Machel.
Riot police clashed with anti-Obama protesters in Soweto.
The American leader was in Soweto to deliver a speech to young African leaders at the University of Johannesburg.
According to Mr Zuma, Mr Mandela remains “stable but critical”, and he added that he had “every hope that he will be out of hospital soon”.