The Israeli Cabinet officially and "unconditionally" condemned apartheid today for the first time, but ministers said the government would make no move to sever diplomatic ties or end the commercial and arms trade between Israel and South Africa.

The declaration came as Chief Gatsha Buthelezi, a leading South African black moderate and head of the country's 6 million Zulus, arrived for a long-scheduled 10-day visit here despite continuing racial violence in South Africa, much of it in his home territory.

Buthelezi, the first South African black opposition figure to visit here, said at an airport news conference that he would urge Israeli leaders to apply pressure to the government of President Pieter W. Botha to end apartheid. He also called for an arms embargo against South Africa because the whites have "most of the weapons."

Prime Minister Shimon Peres, in a declaration accepted by all the Cabinet but not adopted as a formal resolution, said, "The Jewish people's state will not agree to any discrimination on the grounds of race, religion or color, or any other grounds."

It added, "The Cabinet unconditionally objects to the policy of apartheid in South Africa."

But the Cabinet stopped short of even discussing severing diplomatic or trade ties or observing an arms embargo against South Africa. For years, Israel has been reported to have close military ties to Pretoria, including cooperation in the testing of nuclear devices, but the Israeli government has denied those reports persistently.

Although accurate statistics are hard to come by, South Africa is thought to be a leading purchaser of arms from Israel, acquiring as much as 35 percent of Israeli arms exports during the past two decades. Israeli sales to South Africa reportedly have included gunboats and Gabriel missiles.

Communications Minister Amnon Rubenstein, who presented a formal motion to condemn apartheid -- South Africa's policy of strict racial segregation -- said after the Cabinet session that he did not press for economic sanctions because "Israel is in a state where beggars cannot be choosers. We are boycotted by so many countries in the world that where we have trade we cannot afford to give it up."

Rubenstein said Israel's trade with South Africa is only a fraction of what western nations maintain, adding, "If the world community of nations decides to stop all the trade with South Africa, this is a different story."

But, he said, "it would be hypocritical to pick up on Israel and say, 'You alone of all nations stop your rather small trade with South Africa.' "

Israel and South Africa have enjoyed increasingly warm relations since almost all the black African states broke diplomatic ties with Israel between 1967 and 1974. According to South African Foreign Trade Organization figures, Israel exported about $65 million worth of goods to South Africa last year, including animal feeds, canned goods and electronics, and imported about $100 million from there, nearly half of it mineral products such as coal. Israel also reportedly imports nearly $1 billion annually in South African uncut diamonds, but this amount is not included in official trade figures because the diamonds are purchased through London markets.

The published totals also do not include arms sales and services, which many sources say are considerable. Both countries are highly secretive about their arms trade.

Asked why the Peres statement did not also condemn the expanded emergency regulations imposed by South Africa in the face of growing racial violence there, Rubenstein replied: "Nations have to be very careful about how they judge other countries. . . . One must limit one's self to issues of human rights, issues of one's philosophy, one's credo. Israel, too, has emergency regulations but has not used anything like the ferocity used in South Africa."

Peres, in a speech here last night, said that Israel will continue to maintain diplomatic relations with Pretoria, noting that there is a large Jewish community in South Africa. That community numbers about 130,000, and many of them are among the leading foreign financial supporters of Israel.

But Peres said that apartheid is "completely contrary to the very foundations on which Jewish life is based. We can't be expedient in that matter. We are serious, we are definite, we are determined not to accept the policy of discrimination under any circumstances."

Buthelezi's visit, sought by him and scheduled four months ago, well before the current disorders in South Africa began, is seen here as an effort by the black leader to improve relations between Israel and black African countries where Israel maintains unpublicized agricultural and economic development programs but is unable to operate openly.