South Africa's new Foreign Minister Roelof Botha has warned his white country-men to stop "bickering about aparheid" or face up to the threat on a large-scale race war.

Botha made the statement yesterday to a group of some 400 whites in the Johannesburg suburb of West Dene where he is campaigning in a by-election to gain a seat for his party in the South African parliament.

"I'm prepared to go to war over our right to exist," Botha said, "but I'm not prepared to die for signs in a lift." He was referring to such things as segregated elevators.

He told the group that South Africans have "a deplorable lack of appreciaiton of what we are facing, the lateness fo the hour and our place in the order of things."

Botha, 44, is contesting a Johannesburg constituency as a candidate for the ruling National Party. Before being appointed foreign minister, he served as South Africa's ambassador to the United Nations and the United States.

Defending his stand at the United Nations that South Africa would move away from apartheid discrimination, Botha noted that former Prime Minister Hendrix Verwoerd had stated that this was the policy of the South African government 1961.

"The existence of a people is at stake," he said. "One should be actin gon the present. The motives of people who adopt this attitude should not be branded as liberals and they should not be challenged."

He told the group that a conservative U.S. senator who had worked to avoid boycotts and sanctions against South Africa for 35 years could not understand why South Africans were arguing about mixed rugby teams while the Soviets danced; on its country's borders.

"Is this the image which the Afrikaner must defend at the U.N." Botha asked. %The last front for South Africa is the military battle, but South Africa is prepared to talk."

Botha was referring to a meeting he and Premier John Vorster held in Capetown today with the ambassadors of Canada, United States, Britain, France, and West Germany. The group, headed by U.S. Ambassador William Bowdler, presented a joint note to Vorster that reportedly called on South Africa to speed up his plans for independence in Namibia (South-west Africa).

After the meeting the ambassadors issued a short statement saying they gave Vorster their joint views on "achieving as soon as possible an internationally acceptable settlement to the Namibian problem consisstent with (U.N.) Security Council Resolution 385."

Vorster's response to the press was a statement saying "We remains willing to discuss these questions with any government . . . bearing in mind that Southwest Africa belongs to the people of Southwest Africa an dit is their elementary right to solve their own problems in a manner acceptable to the peoples of therir territory."

Vorster has announced plans to set up a government of ethnic groups that was approved at a constitutional convention convened by South Africa last month.The convention was attended by one white delegation and 10 delegations representing black or mixed-race residents of the territory - the latter a South African term for people of mixed racial heritage.