Former president Nelson Mandela left South Africa on Wednesday for a visit to Germany, Tunisia, Libya and the United States, his office said in a statement. On Friday afternoon he will address the 25th anniversary of the German Agency for Technical and Development Cooperation in Frankfurt. Mandela will also pay courtesy calls to Chancellor Gerhard Schroeder and his predecessor, Dr Helmut Kohl, and meet a number of business acquaintances to ‘renew longstanding friendships.’ He will address the Fortsmann Little & Co conference in Aspen, Colorado on September 17 before he returns home.