U.S. President Barack Obama says Nelson Mandela is a "hero for the world" whose legacy will last throughout the ages.
Obama paid tribute to the critically ill anti-apartheid icon on Thursday during an appearance with Senegal's President Macky Sall in Dakar.
President Obama said he also considers Mandela a personal hero. He said his thoughts and prayers were with Mandela's family.
Senegalese President Sall said Mandela is "more than an idol for all of us," and expressed hope that world leaders would learn from his example.
Mandela, who is 94, has spent the past three weeks in a Pretoria hospital, after years of declining health.
Obama plans to visit South Africa during his three-nation tour of the continent and stop at the prison where Mr. Mandela spent nearly two decades.