Mandela, who died in 2013, remains a global icon for his long fight against white-minority rule and for his message of peace and reconciliation when he was released after 27 years in prison.

His birthday on July 18 is marked annually around the world, and the Nelson Mandela Foundation called this year for people to “take action and inspire change” in Mandela’s name.

Obama will set the tone for the celebrations with a speech in Johannesburg on July 17 that aides say will be his most important public address since leaving the White House in 2017.