In this handout provided by the Clinton Foundation, former U.S. President Bill Clinton (R) poses with former South African President Nelson Mandela on the eve of his 94th birthday at his residence July 17, 2012 in Qunu, South Africa.

Former President of South Africa Nelson Mandela and his wife Graca Machel smile and wave to the crowd ahead of the 2010 FIFA World Cup South Africa Final match between Netherlands and Spain at Soccer City Stadium on July 11, 2010 in Johannesburg, South Africa.

circa 1964: Nelson Mandela, President of the African National Congress (left) in discussion with C Andrews, a Cape Town teacher

Nelson Mandela, leader of the African National Congress (ANC), adopts a boxing pose, wearing shorts, t-shirt and boxing gloves, circa 1950. (Photo by Keystone/Hulton Archive/Getty Images)

In this undated file photo Palestinian leader Yasser Arafat is pictured meeting with Nelson Mandela the former leader of South Africa in Gaza City. Medics announced on October 31, 2004 that Arafat's health is in a serious condition, after the illness that has persisted for two weeks, took a sudden turn for the worse.

South African president Nelson Mandela speaks at a conference in the early 1960s. (Photo by Hulton Archive/Getty Images)

1993: Ryan Giggs of Manchester United meets Nelson Mandela of South Africa. Mandatory Credit: David Rogers/Allsport

23 FEB 1995: South African president Nelson mandela (centre) with golfers Nick Price on the left and Greg Norman at a gala dinner to celebrate the inaugural playing of the Alfred Dunhill Challenge between golfers from Southern Africa and Australasia at the Houghton Golf Course, Johannesburg.

1993: Portrait of Manchester United Manager Alex Ferguson and ANC Leader Nelson Mandela during their tour to South Africa. Mandatory Credit: David Rogers/Allsport

Francois Pienaar of South Africa receives the William Webb Ellis Trophy from President Nelson Mandela after the Rugby World Cup final between South Africa and New Zealand held on June 24, 1995 at Ellis Park in Johannesburg, South Africa. South Africa won the match 15-12.

20 MAY 1995: The Womens winner Maria Bak of Germany with South African president Nelson Mandela after the Comrades Marathon in Durban, South Africa.

Nelson Mandela shakes the hand of Alec Stewart of England before the Tour Match between South Africa Invitation XI and England held on October 27, 1995 at the Elkah Oval, in Soweto, South Africa.

3 Feb 1996: Neil Touey of South Africa lifts the African nations Cup with Nelson Mandela on his right hand side after the African Nations Cup final match against Tunisia played in South Africa. The match finished in a 2-0 win for South Africa. Mandatory Credit: Mark Thompson /Allsport

18 Feb 1996: Ernie Els and President Nelson Mandela of South Africa share a laugh as Mandela shows a sketching of Els to the crowd before the final round of the Alfred Dunhill South African PGA Championship at Houghton Golf Club, Johannesburg, South Africa. Mandatory Credit: Allsport UK/Allsport

7/19/98. Gallagher Estate, South Africa. Michael Jackson celebrates Nelson Madela's 80th birthday party and marriage to Graca Mschel, at a party attended by 2000 people

23 May 2000: Nelson Mandela with Academy Members Dawn Fraser, Laureus Sports Awards, Monaco.

23 May 2000: Nelson Mandela with Academy Member Dan Marino, Laureus Sports Awards, Monaco.

23 May 2000: Nelson Mandela with Academy Member Hugo Porta, Laureus Sports Awards, Monaco.

25 May 2000: Nelson Mandela at the Laureus Sports Awards at the Sporting Club Monte Carlo, Monaco.

Nelson Mandela waves his Australian stockman's hat farewell after the Nelson Mandela Tribute Luncheon for World Reconciliation Day September 8, 2000 at the Melbourne Exhibition Centre, in Melbourne, Australia.

Nelson Mandela listens to the Australian Girls Choir during the World Reconciliation Day Concert at the Colonial Stadium September 8, 2000 in Melbourne, Australia. (Photo by Hamish Blair/Liaison)

Ex-South African President Nelson Mandela, left, is greeted by the British Prime Minister Tony Blair at the Celebrate South Africa Concert April 29, 2001 in Trafalgar Square in London, England. The concert was held to celebrate 7 years of democracy in South Africa and to recognize the work of the UK founded Anti-Apartheid Movement. (Photo by Sion Touhig/Newsmakers)

Nelson Mandela is welcomed to the Nelson Mandela Tribute Luncheon for World Reconciliation Day September 8, 2000 at the Melbourne Exhibition Centre, in Melbourne, Australia. (Photo by Hamish Blair/Liaison)

Former South African president Nelson Mandela and his wife Graca Machel arrive at the Royal wedding of Dutch Crown Prince Willem Alexander and Argentine Maxima Zorreguieta on February 2, 2002 in Amsterdam, Netherlands.

Special Olympics World Games 2003, Dublin; Maria Shriver and Nelson Mandela

Nelson Mandela with artists (from left to right) Dave Stewart, Roger Taylor, Brian May, Peter Gabriel, and Annie Lennox photographed at Nelson Mandela's house prior to the 46664 concert in Cape Town, South Africa, on 27 November, 2003.

Nelson Mandela with U2 singer Bono on November 28, 2003.

Nelson Mandela (L), singer Beyonce Knowles (C) and singer Annie Lennox (L) after a press conference for the "46664 - Give One Minute of Your Life to Aids" concert on November 28, 2003 on Robben Island, off the coast of Cape Town, South Africa.

Nelson Mandela makes his way out of the Robben Island prison courtyard after a press conference for "46664 - Give One Minute of Your Life to AIDS" on Robben Island where he was impisoned for 18 years November 28, 2003 off the coast of Cape Town, South Africa.

Oscar winning Actress Charlize Theron wipes away tears as she meets former South African President Nelson Mandela at Mandela House following her Academy Awards success, on March 11, 2004 in Johannesburg, South Africa

Nelson Mandela holds the Olympic Flame on Robben Island during Day 9 of the ATHENS 2004 Olympic Torch Relay June 12, 2004 in Cape Town, South Africa.

Former President of South Africa Nelson Mandela laughs with British Prime Minister Tony Blair as he leaves Downing Street on November 26, 2004 in London, England.

Former South African President Nelson Mandela (L) waves to the crowd with musician and campaigner Bob Geldof before making a speech endorsing the 'Make Poverty History' campaign during a mass rally in Trafalgar Square on February 3, 2005 in London, England.

Singer and actor Will Smith (L-R) talks with former South African President Nelson Mandela and Vice Chairman of MTV Networks & President of MTV International Bill Roedy ahead of tomorrow night's "MTV Base 100th Live!" celebrations, on April 19, 2005 in Johannesburg, South Africa.

Lord Attenborough, and British Prime Minister assist ex-South African President Nelson Mandela to the podium during a statue unveiling ceremony in his honour at Parliament Square on August 29, 2007 in London, England.

Former U.S. President Bill Clinton (L) embraces former South African President Nelson Mandela following remarks by Clinton during a visit to the Nelson Mandela Foundation July 19, 2007 in Johannesburg.

Ex-South African President Nelson Mandela has his head caressed by his wife Graca Machel during a statue unveiling ceremony in his honour at Parliament Square on August 29, 2007 in London, England.

Ex-South African President Nelson Mandela addresses the crowd during a statue unveiling ceremony in his honour at Parliament Square on August 29, 2007 in London, England.

Actor Morgan Freeman (L) and Nelson Mandela attend the 'Unite For A Better World Gala Dinner' on September 2, 2007 at the Hotel de Paris in Monte Carlo, Monaco.

British Prime Minister Gordon Brown applauds ex-South African President Nelson Mandela during a statue unveiling ceremony in Nelson Mandela's honour at Parliament Square on August 29, 2007 in London

Former South Africa President Nelson Mandela poses with South Africa Rugby Union coach Jake White (L), South Africa Rugby Union captain John Smit (R) and the Webb-Ellis cup during the Springboks visit to Nelson Mandela at his residence on October 27, 2007 in Houghton, Johannesburg, South Africa.

In this handout from Nelson Mandela Foundation, former South African president and Nobel peace prize laureate Nelson Mandela blows out the candles on his birthday cake received from the staff in honour his 90th birthday, at the Nelson Mandela Foundation August 5, 2008 in Houghton, Johannesburg

In this handout from Nelson Mandela Foundation, former South African president and Nobel peace prize laureate Nelson Mandela and his wife Graca Machel share a laugh with Boniswa Qabaka (C) whilst wrapped up in a blanket, a gift received from the staff in honour his 90th birthday, at the Nelson Mandela Foundation August 5, 2008 in Houghton, Johannesburg

Rwandan President Paul Kagame meets former South African President Nelson Mandela at the Nelson Mandela Foundation March 20, 2009 in Johannesburg, South Africa.

Celebrity Chef Gordon Ramsay (R) shakes hands with Nelson Mandela during a lunch to Benefit the Mandela Children's Foundation as part of the celebrations of the opening of the new One&Only Cape Town resort on April 3, 2009 in Cape Town, South Africa.

Former South African President Nelson Mandela sits on stage as ANC party members dance April 19, 2009 in Johannesburg, South Africa.