Washington - US President Barack Obama said on Thursday he was "deeply concerned" for the health of Nelson Mandela, after the former president was again admitted to hospital.
"We are deeply concerned with Nelson Mandela's health - he is a hero, I think, to all of us," Obama said as he met four leaders from sub-Saharan Africa at the White House.
"We will be keeping him in our thoughts and prayers, and his entire family," Obama said.
"He is as strong physically as he has been in character and in leadership over so many decades. Hopefully he will come out of this latest challenge."
Mandela, 94, was readmitted to hospital with a lung infection, the latest health scare for the much-loved anti-apartheid icon.
Earlier, President Jacob Zuma said there was no need to panic over Mandela being in hospital
Zuma told the BBC that the 94-year-old Mandela is "in good hands" and the "country must not panic".