Andrew Young, the U.S. ambassador to the United Nations has predicted a peaceful Rhodesian settlement "within the next few weeks" if there is a speedy solution to the Namibia problem in which U.N. forces replace South African ones.

In an interview that is to appear today in the Paris newspaper Le Matin, Young says that chances of peace in Rhodesia hang on the outcome of the current talks involving the major Western powers seeking a settlement in Namibia, which South Africa administers under the name Southwest Africa.

"If South Africa pulls out its troops and they are replaced by U.N. troops, I would say that the chance of seeing a similar agreement on Rhodesia within the next few weeks is very good," Young said in the interview, given in Geneva Monday.

Namibia and Rhodesia will "certainly go one way or the other before the end of the summer," he said.

"With a settlement in Namibia, the violence will stop, U.N. troops will move in and the whites in South Africa and Rhodesia will see that it works."

Young said of the black-white conflict in Rhodesia, "It's a family feud much more than people realize." He said that the black nationalist leaders and Rhodesia Prime Minister Ian Smith have been in constant touch over the years.

Like any family feud, he said, it sometimes turns ugly. Young recalled a recent statement to him by Rhodesian black leader Robert Mugabe that Mugabe's mother "would never forgive him" if anything ever happened to Smith's parents, who are farmers in the countryside, because they had help the Mugabe family out of great personal difficulties.

Turning to Angola, Young said that he had met in Nigeria with Angolan President Aghostino Neto in February 1977 and that there were regular contacts for a long time with the Angolan leader preceding the recent U.S. mission to the Angolan capital, Luanda. Young said the normal U.S. relations with Angola are now envisaged.

He said that his aide, Don McHenry, had met twice Neto and that the U.S. ambassador to Nigeria had gone to Luanda to see Neto several times.

Young said that it had taken a long time to establish ties because Neto would not hear of U.S. proposals that he seek a reconciliation with rival leader Jonas Savimbi, whose movement in southern Angola is thought to control at least a third of the country.

Young said an Angolan-American repprochement was worked out on the basis of working together for a Namibian settlement. Namibia borders Angola to the south.

As long as Angola is not stable, Young said, then "whether we like it or not," its northern neighbor Zaire cannot be stable either. Tribal links overlap so much over the Zaire-Angola frontiers, he said, that there cannot be conflict on one side of the border without it spilling over to the other.

In an earlier half of the interview, published yesterday by Le Matin, Young expressed grave reservations about the French role in Zaire and said that any positive results they had produced there were canceled out by French covert activities in support of Svimbi in Angola.

France's "left hand may be destroying in Angola what its right hand builds in Zaire," he said.

He contrasted Belgian and American help to the besieged whites in Zaire's Shaba Province to France's attempts to further its economic interests in Africa. He spoke of France's "very fruitful" relations with such former French colonies as Ivory Coast.

Young said that he shared President Carter's view that the Cubans must bear a part of the responsibility for the invasion of Shaba because the Cubans trained the invaders' Angolan military patrons.Young said the Cubans did not discourage the invasion because they did not want to betray their East German friends.

The East Germans, Young said, are becoming increasingly active in providing military training in Africa and were particularly upset about the presence in western Shaba of a West German missile development program. That program has been described in Western European papers as an insignificant operation run by a small private West German company.