Barack Obama has described Nelson Mandela as a “hero for the world” as well as a “personal hero”, adding that his legacy “will linger on throughout the ages”.
The US president was speaking as he met his counterpart in Senegal on the first leg of his African tour.
At a joint news conference with President Macky Sall in Dakar, Obama described how Mandela had inspired him to get involved in political activism.
The former South African president, he said, believed in the basic principle of treating people equally and was willing to sacrifice his life for that belief.
The US leader is also due to visit South Africa and Tanzania.
He told his Senegalese hosts that the West African country was a “great example” of good governance and praised the continent generally for its progress in achieving democracy.