Former US president Barack Obama will deliver the annual Nelson Mandela memorial lecture at a 4,000-capacity arena in Johannesburg in July, South African organisers announced on Monday.
Obama, who met with Mandela in 2005 and who made an emotional address at his funeral, will speak at the lecture marking 100 years since the anti-apartheid icon was born.
"President Barack Obama -- we will be looking forward to hosting him as he will be addressing this esteemed Nelson Mandela annual lecture," Sello Hatang, head of the Nelson Mandela Foundation, said.
Hatang said the foundation had been seeking someone with "an Africa heritage" to deliver an address that will "deal with issues of democracy" facing the world today.
"We thought who can (better) represent the legacy of Madiba than the person who we believe took on the baton when he became president of his own country," Hatang, using Mandela's clan name.
The announcement was made at Constitutional Hill in Johannesburg, a former jail where anti-apartheid activists such as Mandela's late former wife Winnie, were incarcerated.
The complex is now a museum and hosts the country's Constitutional Court.
- 'Two legacies join' -
Hatang told AFP that Mandela was "elated" when Obama was elected in 2008 "because he saw it as a moment in American history".
"We hope that it will again be a significant moment for the two legacies to join," he said.
Hatang said the lecture, coming a year before South Africa's national elections, "will be a significant moment where we will be talking about active citizenry and how do you build an active citizenry."
He also said one lesson expected from the lecture is "that all of us carry a responsibility to deal with anti-black racism".
The New York Times said that Obama would spend five days in Johannesburg holding meetings, workshops and training for 200 young people in his most significant international project as an ex-president.
In his funeral address, Obama said Mandela "makes me want to be a better man" and hailed him as "the last great liberator of the 20th century".
Mandela was imprisoned for 27 years under white-minority apartheid rule before his release in 1990 and his victory in the first multi-race election in 1994.
He served one term as South Africa's president before stepping down in 1999. He died in 2013, aged 95.
Former Nelson Mandela lecture speakers include Bill Clinton, Thabo Mbeki, Kofi Annan, Bill Gates and Archbishop Emeritus Desmond Tutu.
Obama's lecture will be at the Ellis Park Arena on July 17, a day before Mandela's birthday.