More than 60,000 people gathered in Johannesburg Tuesday for a memorial service to honor late South African President Nelson Mandela.
A steady rain did not stop mourners from singing and dancing in tribute to Mr. Mandela, as speakers praised his role in ending apartheid and healing South Africa's racial divisions.
U.N. Secretary-General Ban Ki-moon said Mr. Mandela's passing is an enormous loss.
"South Africa has lost a hero. You have lost a father. The world has lost a beloved friend and mentor. Nelson Mandela was more than one of the greatest leaders of our time, he was one of our greatest teachers."
U.S. President Barack Obama said Mr. Mandela, and South Africa, showed how fights for freedom and human rights can be won.
"Nelson Mandela reminds us that it always seems impossible until it is done. South Africa shows that is true. South Africa shows we can change. That we can choose a world defined not by our differences, but by our common hopes. We can choose a world defined not by conflict, but by peace and justice and opportunity."
South African President Jacob Zuma noted the service takes place on the 20th anniversary that Mr. Mandela was awarded the Nobel Peace Prize.
Mr. Mandela became South Africa's first black president in 1994, after being imprisoned for 27 years for his role in the struggle against white minority rule.
The service was held in Johannesburg's main stadium used for the 2010 World Cup football (soccer) finals.
The venue is also the place where Mr. Mandela made his last public appearance at the closing ceremony of the first-ever World Cup in Africa.
Along with President Obama, the U.S. delegation included first lady Michelle Obama and former Presidents George W. Bush, Bill Clinton and Jimmy Carter.
Mr. Mandela's remains will lie in state at the Union Buildings in Pretoria -- the official seat of the South African government -- on Wednesday, Thursday and Friday.
The memorials and events will culminate in Mr. Mandela's burial on December 15 in his boyhood home village of Qunu.