WATCH: Barack Obama delivers Mandela centenary address in Joburg

Former US president Barack Obama is scheduled to deliver the annual Nelson Mandela lecture at the Wanderers Stadium in Johannesburg where a crowd of about 9 000 people is expected.

The lecture, in partnership with the Motsepe Foundation, comes a day before Nelson Mandela International Day and is themed: "Renewing the Mandela Legacy and Promoting Active Citizenship in a Changing World". 

The Nelson Mandela Foundation said on its website that the lecture would focus on "creating conditions for bridging divides, working across ideological lines, and resisting oppression and inequality".