Mrs Obama going to Soweto
Johannesburg - After an unplanned meeting with Nelson Mandela at his Houghton home, US First Lady Michelle Obama will be in Soweto on Wednesday.
Obama is set to go to a number of historical sites in the area with her daughters, mother, niece and nephew.
The first lady met a healthy-looking Mandela on Tuesday - an unexpected encounter with the former South African president and anti-apartheid icon who has largely retired from public life.
A photo provided by the Nelson Mandela Foundation showed the 92-year-old Mandela sitting on a couch next to Mrs Obama, pen in hand to sign an advance copy of his new book, Nelson Mandela By Himself: The Authorised Quotations Book.
Mandela sent word for meeting
Mandela was wearing one of his trademark shirts, richly patterned and buttoned at the neck.
Mrs Obama, daughters Malia and Sasha, and her mother, Marian Robinson, were viewing some of Mandela's personal papers at his foundation on Tuesday when he sent word that he wanted to meet them at his home in a leafy Johannesburg neighbourhood.
It was the first meeting between America's first black first lady and the political prisoner who later became his country's first black president.
The American president's family spent about 20 minutes with Mandela and his wife, Graça Machel, who is a former first lady of Mozambique.
Mrs Obama's niece and nephew, Leslie Robinson, 15, and Avery Robinson, 19, who are travelling with her, were also invited to meet Mandela.
Mandela, who stepped down in 1999 after serving one term as president, is rarely seen in public anymore.
He is in fragile health and was briefly hospitalised in January with an acute respiratory infection.
President Obama, Mandela met before
Mrs Obama is travelling without President Barack Obama, who met Mandela in Washington in 2005 when he was a US senator.
Obama and Mandela have spoken by telephone several times since Obama took office, most recently last June, the White House said. The president also wrote a foreword for Mandela's book, Conversations with Myself.
The US first lady began a weeklong goodwill visit to South Africa and Botswana on Monday.
Earlier on Tuesday, she met with Nompumelelo Ntuli-Zuma, a wife of South African President Jacob Zuma, who has three of them.
Mrs Obama and her family ended the day with a tour of the Apartheid Museum.