US President Barack Obama (2nd L) and First lady Michelle Obama (L) are greeted by South Africa's President Jacob Zuma (2nd R) and South African First lady Thobeka Madiba-Zuma at an official dinner in Pretoria June 29, 2013. [Photo/Agencies]

US first lady Michelle Obama (R) hugs Miriam Kgokane, 10, after participating in a virtual discussion event with youths at the Sci-Bono Discovery Centre in Johannesburg June 29, 2013. The first lady was joined by teenagers from across South Africa as well as US students virtually, at the event organized in conjunction with MTV Base, an African youth and music TV channel, and Google Plus. [Photo/Agencies]