Minister in the Presidency Collins Chabane will replace President Jacob Zuma at Saturday's Youth Day celebrations in Port Elizabeth.
Zuma was attending the G20 summit in Mexico from Monday.
The Mail & Guardian Online reported on Friday Zuma rejected the invitation to speak at the National Youth Development Agency's (NYDA) event on Saturday.
The African National Congress called on all South Africans, particularly the youth, to join in the commemoration of Youth Day.
“The sacrifices and achievements attained by the 1976 youth should be defended by all South Africans at all times,” spokesman Jackson Mthembu said.
The youth had to celebrate June 16 in honour of their forebearers who sacrificed everything in defence of their right to an education, he said.
The Congress of SA Trade Unions said the heroes and heroines of June 16, 1976, paved the way for South Africa's democracy. This year's Youth Day celebrations coincided with the 20th anniversary of the Boipatong massacre, the trade union federation said.
While the 1976 Soweto uprisings were being commemorated, the current socio-economic plight of young South Africans should be recognised, Cosatu said.
Congress of the People president Mosiuoa Lekota called on the country's youth to get educated.
“The youth must demand from their parents, teachers, communities and government an increased investment in their education and training.”
The United Democratic Movement Youth Vanguard said those who made the ultimate sacrifice would be remembered on June 16.
“We want to praise those who have taken the baton from the youth who came before us – thank you for your dedication and sacrifice,” president Teddy Thwala said.
Young South Africans however had been cheated out of a proper education and jobs due to government corruption, he added. - Sapa