South African Foreign Minister Roelof F. (Pik) Botha charged yesterday that U.S. pressure on his nation's racial policy is a product of America's own black-white problems and an attempt "to outplay the Russians" in Africa.

"Why should we beat about the bush about these matters?" Botha said at an emotional press conference, ending four days of private talks here.

At a subsequent press conference in New York, after meeting with U.N. Secretary General Kurt Waldheim, Botha said that South Africa is prepared to stand "completely alone" if necessary, to support its own principles.

If American and other western investment is withdrawn from South Africa as punitive action to force changes in racial policy, Botha said, "this would be to our disadvantage."

"But it would not be that serious that it would cripple the economy," Botha said. "In fact it might even do us a lot of good not to have such a fast growth rate which would cause inflation."

In his Washington and New York press meetings yesterday before returning to South Africa, Botha evidently was seeking to build a crossfire againt the new pressure mounted against his nation's racial apartheid policy by the Carter administration in the last two months.

At the same time, South African diplomatic sources sought to convey the impression that Botha's private talks with Secretary of State Cyrus R. Vance and other U.S. officials were productive. But American sources said the private discussions equally failed to narrow the gap between the two nations. One administration source said, "I think there's a certain effort to put is on the defensive and to take the pressure off them."

Botha told American newsmen that the Carter administration's human rights policy is "completely inconsistent." He said, "You are demanding from us, or applying to us, norms which you do not apply to the rest of the world."

Botha said this is in part a product of "your internal problem," and also an attempt "to outplay the Russians in Africa by trying to be more radical than they are."

Asked if he was charging the Carter administration with playing domestic politics, Botha said he was simply noting from his own experience here as an ambassador that "you've got an internal black-white problem" and "it is a fact that this question plays a role in elections in this country."

State Department press spokesman Hodding Carter denied that the United States is singling out South Africa for special demands to improve human rights in a nation where whites are outnumbered almost five to one by non-whites. Carter said "I reject" the claims of political motivation and an effort to be more "radical" than the Soviet Union.

The United States is not confronted South Africa with "a roadmap" or any fixed timetable for sharing power, Carter said. The problem, he said, is that "the South African government has continued to repudiate all proposals for power-sharing."

Botha, during the past week, has reiterated that the demand of "one-man, one-vote" for South Africa, which Vice President endorsed last month after meeing with South African Prime Minister John Vorster, means "our destruction."

Although Americans in general disagree with South Africa's racial policy, Botha said yesterday, "the overwhelming majority of Americans would equally not wish us to be destroyed . . ."

Administration officials maintain that Botha has developed "a straw man" issue of instantenous one-man, one-vote. Botha countered yesterday, "I don't think it really matters if you tell a man he is going to hang tomorrow, or next week." But he also said that if the U.S. objectice is "full participation by various roads, then we can start talking."

Botha said South Africa has done all that is possible to help move white-ruled Namibia (Southwest Africa) and Rhodesia toward independence and majority rights.