South Africa's acceptance of a U.S.-mediated plan for ending foreign military involvement in southwestern Africa has cleared the way for a permanent settlement in the troubled region, officials say.

Pretoria Tuesday formally announced its acceptance of the plan, which calls for the withdrawal of 50,000 Cuban troops from Angola and the granting of independence to Namibia after 73 years of South African rule.Cuba and Angola had already accepted the proposal, which was hammered out last week by negotiators in Geneva.

"A major and very important step has been taken on this long, long road," Foreign Minister Roelof "Pik" Botha told a news conference.

Botha said his government informed the United States of South Africa's acceptance of a proposed timetable for Cuban troop withdrawal reached in talks mediated by U.S. Assistant Secretary of State Chester Crocker. Disagreements over the timetable had posed an obstacle in previous negotiations.

Botha said the accord could be formally signed in the Congolese capital of Brazzaville "hopefully in the next week or two."

In Washington, State Department spokesman Charles Redman said South African acceptance of the plan means "the way is now clear to completion of the negotiations and the signing of the interlocking set of agreements the parties have agreed to conclude."

U.N. Secretary-General Javier Perez de Cuellar lauded South Africa's acceptance of the settlement.

"The secretary-general is glad to note that all the parties to the quadripartite talks have now confirmed their agreement to the decisions reached in Geneva last week to facilitate a settlement in southwestern Africa," Perez de Cuellar said in a statement.

His statement urged "all the parties to redouble their efforts to achieve a final settlement."

The South African announcement came a day after negotiators from Cuba and Angola began meeting in New York to reach a final agreement. Botha said the current talks involve the means for verifying the Cuban withdrawal.

South Africa has insisted that, in return for granting Namibia independence, the Cuban troops be simultaneously withdrawn from neighboring Angola.

Cuban forces were dispatched to Angola to bolster the Soviet-backed government in a civil war against Jonas Savimbi's UNITA rebels assisted by the United States and South Africa following independence in 1975.