Talks in S. Africa please UN chief

United Nations Secretary-General Javier Perez de Cuellar left South Africa, reporting ''substantial progress'' on the question of independence for Namibia. But his progress came on nuts-and-bolts issues and does not mean a settlement in the disputed territory is any closer, reports Monitor correspondent Paul Van Slambrouck. One of the chief issues in the Namibian debate - the presence of Cuban troops in Angola - is outside the Secretary-General's mandate on this trip. South Africa insists that Cuban troops be withdrawn in conjunction with a settlement on Namibia.

Nevertheless, the Secretary-General described his visit as ''most useful.'' The UN plan for independence in Namibia calls for a cease-fire that would be monitored by the UN's transitional assistance group (UNTAG). South Africa has voiced concerns about the composition of UNTAG in the past, but now says the issue has been resolved.

Pretoria also has backed away from a Namibia settlement in the past, because of alleged UN bias. Analysts say the Secretary-General's trip here will help to head off any such charges in the future. South African Foreign Minister Roelof Botha said that the UN Secretary-General has given ''unambiguous assurances'' that the implementation of a settlement would be fair.

Mr. Perez de Cuellar now visits Namibia, and then he will go to Angola. He plans to meet with officials from the South West People's Organization, the black-nationalist group fighting South African forces for Namibian independence. To date, there has been no mention of whether he would meet Angolan officals or in any way discuss the Cuban issue.