Obama met privately with Mandela's family on Saturday at the Nelson Mandela Centre of Memory in Johannesburg. He and first lady Michelle Obama met with Mandela's daughters and six grandchildren, offering them words of comfort.

Whilst in South Africa, the Obamas do not plan to meet with Mandela, who remains hospitalized in critical condition in Pretoria, where he has been treated for a lung infection for three weeks.

During a press conference with President Jacob Zuma on Saturday, Obama referred to Mandela as "one of the greatest people in history."

"Madiba's [Mandela's clan name] moral courage and this country's historic transition to freedom and a democratic nation are a personal inspiration to me and an inspiration to the world," Obama said.

US-African economic ties

Obama, whilst showing respect and sensitivity to the grave health of South Africa's beloved anti-apartheid leader, has also tried to focus on expanding US-African trade and strengthening US economic ties with Africa.

The US president, who has been greeted by cheers as well as protesters in South Africa, has talked about the importance of stable institutions and Africa's economic potential.

On Saturday, he responded to naysayers who have accused him of only wanting to invest personal capital in Africa as a response to increased interest in the continent by China, India, Brazil and others.

"I want everybody playing in Africa," he said. "The more, the merrier." But he was also careful to point out that Africans should ensure that foreign economic ties are also a "good deal for Africa."

"If somebody says they want to come build something here, are they hiring African workers?" Obama said. "If somebody says that they want to help you develop your natural resources, how much of the money is staying in Africa?"

Also on Saturday, Obama met with young people in Soweto, an area of Johannesburg that was central to the youth-driven movement against the former South African apartheid government.

A glance toward legacies

Obama will continue to show respect for Mandela and his legacy on Sunday by visiting Robben Island, where Mandela spent 18 of his 27 years in prison.

The visit to the prison will set the stage for Obama's key address of his eight-day African tour. He will deliver a speech at the University of Cape Town, where Robert F. Kennedy gave his 1966 "Day of Affirmation" speech, boosting the anti-apartheid movement.

In the address, Obama is expected to challenge Africans to renew efforts to expand economic growth and democracy whilst extolling the legacies of Nelson Mandela and the US civil rights movement.

tm/ccp (dpa, AP, AFP, Reuters)