JOHANNESBURG, SEPT. 12 -- The white South African government today asked other nations to help end violence in nearby black townships by urging African National Congress leader Nelson Mandela to meet with his chief political opponent, whose followers have been blamed for the fighting.

At least 50 people have been killed since Mandela and President Frederik W. de Klerk held talks Tuesday on ways to end the four-week-old factional fighting in Johannesburg's black townships. The violence has claimed more than 700 lives in the last month.

Mandela so far has refused to meet Zulu Chief Mangosuthu Buthelezi, whose Inkatha Movement the ANC accuses of launching attacks on township residents supporting the ANC. Mandela has said such a meeting would be tantamount to giving in to violence.

Mandela said Tuesday that the fighting threatens negotiations between the ANC and government for a new political order in South Africa. The ANC says Inkatha has resorted to violence to gain entry to the talks, and that white extremists are fomenting much of it to set back progress on abolishing the apartheid system of racial separation.

In a letter to U.N. Secretary General Javier Perez de Cuellar, Foreign Minister Roelof F. Botha said, "I have appealed to governments through local diplomatic representatives to use their influence to bring about such a meeting.

"But I believe it would be useful if the international community could issue a public appeal to the two leaders to join forces in putting an end to the bloodshed."