The 10th anniversary of the Soweto uprising of 1976 will be commemorated on June 16, a day that has become a symbol of black aspirations for freedom, equal rights, and full political participation. On this solemn occasion, it seems fitting that the U.S. Government renew its call on all parties to exercise maximum restraint in searching for solutions to South Africa's severe political crisis. Violence by those who enforce apartheid and by those opposed to it has become so common that South Africa risks becoming a continuing tragedy.
The American people feel strongly that permitting nonviolent meetings is the hallmark of civilized governments and in the best tradition of the Western democracies. I have communicated directly with President Botha to ensure that he and his government are aware of my deep feelings about this. At the same time, I want to address myself publicly to all South Africans to urge that they consider again the stark consequences of violence before lighting the next match or pulling the next trigger. Our hearts are with the people of South Africa in this time of trauma. We appeal to them—white and black—to face up to their own responsibilities to make the Soweto anniversary truly a time for peaceful expressions of opposition to apartheid. Only in this way will they truly honor those who died in Soweto 10 years ago and the millions of South Africans still yearning for justice in that land.
Ronald Reagan, Statement on the 10th Anniversary of the Soweto Uprising in South Africa Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/258706