South African Foreign Minister Roelof F. (Pik) Botha said yesterday that his country has conceded that it must move away from apartheid, adding that the major policy address delivered Thursday by South Africa's president did not get the credit it deserved because public expectations had been improperly raised.

But national security affairs adviser Robert C. McFarlane, who met with Botha in Vienna in the days leading up to the speech, said that he had been led to believe that the address would contain more concessions to South Africa's black majority. "The South African government this week has labored and produced a cloud," McFarlane said.

"I think the spectrum of possibilities discussed in Vienna included more than was announced last Thursday," he said. Asked if he was disappointed in the speech, he said, "As long as there's apartheid, we're going to be disappointed."

The two governments engaged in a round of electronic diplomacy as key figures appeared on U.S. television shows. Botha was on CBS' "Face the Nation," and McFarlane was on ABC's "This Week With David Brinkley."

At the heart of the sparring was last week's speech by South African President Pieter W. Botha (who is not related to the foreign minister), which failed to announce expected reforms in the country's system of white minority rule.

The foreign minister denied that he was responsible for the heightened expectations and said that South Africa's president had gone further than expected.

Despite McFarlane's expressed disappointment with the speech, he said President Botha's call for negotiations on a new constitutional structure was a positive sign.

"I do think it's possible, only possible, that a second-level reflection after a couple of more days may lead these leaders on both sides who are looking into the abyss of massive violence to simply say: Does it cost us that much to sit down, challenge this government, ask them to . . . turn the rhetoric into reality?" McFarlane said.

But Botha said the South African government is moving away from apartheid. "We have accepted that there won't be first-class and second-class citizenship . . . .We have conceded that . . . . What more can we do?" Botha asked.

"The whole world seems to concentrate on black grievances," the foreign minister said. "But you forget we also have a white constituency who would like to live, would like to survive in this country, who have also made a contribution." He said that some who are pushing for black participation in South Africa's political process are asking whites "to surrender their participation."

McFarlane said President Reagan still supports "constructive engagement" in South Africa, but added that the administration is not "cozying up" to the South African government. Instead, he said, it is "trying to use our influence" to turn the Botha government away from apartheid. "That policy has gotten results, and the president is committed to carrying it on."

Referring to statements by South African officials that "equality is envisioned at the end of this process," McFarlane said: "Let's challenge the government, sit down, find out what does all this rhetoric mean. Is it a good faith commitment to negotiated peaceful evolution from apartheid? Who knows? You can't tell from the speech."

Citing statements about black citizenship and control of population movements, McFarlane said, "The black leadership doesn't risk a lot by sitting down and saying, 'What do you mean by your citizenship rhetoric, what do you mean by what you said about influx control . . . ? Do you intend to negotiate a process or not? That will become quickly evident' . . . ."

He stopped short of predicting whether Reagan will veto legislation to provide economic sanctions against South Africa. A final version of that bill is pending in the Senate after easily passing the House.

McFarlane said Reagan supports parts of the various bills pending in Congress. "I think all the bills are natural expressions of American values and the impulse to do something -- even if it may be wrong. Some are measures that the president surely can accept," he said.

But he said that banning U.S. investment in South Africa would "hurt the very people you're trying to help . . . . The president believes it is not up to the United States to prescribe what is right for other people."