President Nelson Mandela said this shift did not conflict with regional attempts to broker a cease-fire in the Democratic Republic of Congo.

President Laurent Kabila's allies are finding support from the South African Government

He said that in the face of aggression, President Kabila had the right as a sovereign leader to call for military assistance from his allies.

Mr Mandela was speaking after a meeting of Southern African Development Community members, attended by United Nations Secretary General, Kofi Annan.

Greg Barrow describes South Africa's surprise move

BBC correspondent Greg Barrow reports that one South African official said military intervention had helped to create a certain balance between the warring parties in Congo and could help lead towards a cease-fire.

This view was echoed by Mr Mandela at a news conference held with Kofi Annan, and the Secretary General of the Organisation of African Unity, Salim Ahmed Salim.

All three men attended a meeting of heads of state from the Southern African Development Community, called to discuss the conflict in Congo.

The view expressed by Mr Mandela was that in his capacity as President of the Democratic Republic of Congo, Laurent Kabila had the right to call for assistance from his allies in Zimbabwe, Angola and Namibia.

South African officials now say that a diplomatic initiative can work hand-in-hand with military intervention.

Kofi Annan: Encouraged by his conversations with African leaders

Mr Annan said the issue now is to bring about a cease-fire and the eventual withdrawal of foreign troops from Congo. He is holding meetings with the Ugandan and Rwanda leaders during the day.

The BBC's correpsondent says their analysis of the conflict is likely to sharply differ from what Mr Annan has heard from President Kabila. But despite potential obstacles, Mr Annan said everybody involved in Congo wanted peace.