Andrew Young, the U.S. Ambassador to the United Nations, said yesterday that U.S. troops might be used as part of a U.N. "peace-keeping" force in Rhodesia, but would never be sent into combat in that country or South Africa.

Young said that because the U.S. Army has "the only really intergrated military units" in the world, "they could play a role in peace-making" in Rhodesia. But he said it would be hard to gain public or congressional approval for even a non-combat role.

White House press secretary Jody Powell said later that the use of U.S troops in Rhodesia is not a serious policy option being considered by the administration.

"I don't know any real consideration of that at this point," Powell said."I'm sure Andy was speaking of a very hypothetical situation."

As for any possible involvement in South Africa, should the white-minority government there come under military attack, Young said, "I see no situation in which we would have to come in on the side of the South Africans . . . You'd have civil war at home. Maybe I ought not to say that, but I really believe it. An armed forces that is 30 per cent black isn't going to fight on the side of the South Africans. This President has too much understanding . . . of white racism ever to align himself with it."

In a wide-ranging interview, the former Georgia congressman also said:

He hoped to avoid vetoing a resolution on apartheid in the U.N. Security Council this month, either by softening it to the point it is not "totally destructive" of the South African government or by postponing its consideration.

Majority rule in South Africa is likely "within 10 years," but the regime is currently strong enough to put down any internal or external threat to its existence.

There is no real danger from Soviet or Cuban military operations in southern Africa, because "there isn't a rebel group that won't turn to the United States" for trade and economic dealings "once it's in power."

The Cuban intervention in Angola is turning into "a South Vietnam. It's a huge country. The Cubans don't have the forces to stabilize it. They're in a war of attrition . . . A dozen or so bodies are going back to Cuba every week - maybe more - and people are asking, "What are we doing, dying, over there?'"

The administration's human'rights offensive will not exempt any countries. "There will be initiatives involving South Korea and the Philippines. There have been personal messages sent already . . . There isn't anybody safe" from the kind of pressure the Carter administration is bringing on behalf of individual freedom.

Repeatedly in the 90-minute interview, Young stressed that he was not operating independent of foreign policy direction from the President and Secretary of State or trying to build an "empire" of his own from the U.N. Mission.

Saying he had filled key roles on his staff with people suggested by Secretary of State Cyrus R. Vance, the ambassador said he had gone to both President Carter and Vance when criticism emerged about his earlier public statements and offered to "cool it."

Far from discouraging him, he said they assured him he would not have "any flak" from them. Last week, presidential press secretary Jody Powell called him to say, "From where I sit, you're looking awfully good."

Young also argued that his outspoken advocacy of human rights and majority rule in Africa was having benefits for the United States and the cause of peace around the world.

"If we don't take interest in human rights in southern Africa," Young said, "We can't count on Nigeria to supply oil. We have a bloc of 47 nations automatically against us in every international forum. They can't destroy us, but they can be very disruptive for out initiatives, say, in the Middle East."

The ambassador said the campaign for human rights in Africa had already produced "some softening of the rhetoric" of the African countries against Israel. "I've always maintained that hositility to Israel was connected to the neglect of Africa," he said.

"When they couldn't get our attention any other way, they got it by attacking Israel. Now that Africa is getting attention, they're on the verge of becoming very cooperative."

Young said the cooperation extended to the drafting of the resolution condemning apartheid in South Africa, which is expected to come before the Security Council this month, while he is its president.

At one point in the interview he said "it might not come up," but later said he thought it more likely that some kind of resolution would be offered.

Young said he was striving for wording that allowed countries to "oppose apartheild and not be totally destructive of the South African government." Personally, he said, he would willingly support a Swedish resolution to ban all future investment in South Africa, but added, "We still haven't made a policy decision on that" in the Carter administration.

If full-scale warfare breaks out in Rhodesia, Young said, "We'd just stand around and pick up the pieces, or else send in a U.N. peace force or a [British] Commonwealth peace force.

"There are a number of alternatives, but U.S. troops are not one of them. We couldn't do that without risk of a clash with the Russians - unless it were done as part of a U.N. peace force. In a sense, I regret that, because the transition period is critical, and no one has any confidence in the British."