South Africa's top representative in Namibia (Southwest Africa) expressed pessimism yesterday about finding an internationally acceptable formula to bring this territory to independence.

"It is time the world realized we won't be pressured," Marthinus J. Steyn, the South African administration general of Namibia, said in an interview.

Steyn spoke as President Carter, flying from Nigeria to Liberia, was warning South Africa that failure to accept the West's proposals for a negotiated transfer of power in Namibia could worsen relations between the United States and South Africa.

South Africa, Steyn said, is "not here to surrender."

"We are here to achieve the greatest amount of good for the people with the least violence and in the shortest period of time," he said. "Those who want to pressure us are greatly mistaken."

Steyn, whose job is to prepare the territory for elections leading to independence, said he did not think that the chief black nationalist movement, the Southwest Africa Peoples Origanizations, will participate in the elections.

He acknowledged that any election without SWAPO's participation would probably mean an internsification of the guerrilla war in nothern Namibia, along the Angolan border, between Cuban-aided SWAPO and routh African soldiers.

"If there has to be war, let there be," Steyn said.

South Africa has expressed willingness to grant independence to Namibia, but it is trying to install a government that will be friendly to South Africa's white-minority government. The West proposes a free election under U.N. supervision.

SWAPO has opposed participation in a transfer of power under terms dicated by South Africa.

Meanwhile, Relations between SWAPO supporters and followers of Slain Hereo Chief Clemens Kapuuo, who was assassinated here a week ago, are extremely sensitive, according to both South African and SWAPO officials.

The Hereros have accused SWAPO of killing Kapuuo, who has president of the Democratic Turnhalle Alliance, a multiracial coalition of ethnically constitud parties that opposed SWAPO. Kapuuo was the second alliance leader to be killed in six weeks. Police have arrested no one in connection with his slaying.

Top SWAPO leaders have left Windhoek following threats against their lives and in the black residential area of Katutura outside Windhoek, relations between the two groups are very tense, SWAPO is administrative secretary, Axel Johannes, said.

Four homes of SWAPO supporters have been burned by Hereos, Johnannes said. Yesterday a SWAPO regional chairman claimed there had been an attempt on his life Saturday night at his home in nothern Namibia.

Steyn has warned he will take measures to reduce political violence but refused to give details.

"I cannot let this escalate into a war between Hereros and Owambos," the tribal group that traditionally supports SWAPO, he said.

Steyn said he wanted "to be careful not to take unnecessarily severe actions," but he added that SWAPO "would have to decide whether it is going to be a political party or a terrorist organization."

News services reported these developments:

Two Rhodesian-based black nationalist parties rejected President Carter's call for a new Rhodesia settlement conference.

The United African National Council of Bishop Abel Muzorewa described Carter's proposal as fruitless and "impudent."

The African National Council of the Rev. Ndabaningi Sithole said the March 3 agreement reached with Prime Minister Ian Smith, which Carter wants to overturn, is "final and unalterable."

The British Foreign Office announced that American and British envoys will soon start a tour of southern Africa to meet with likely participants in the proposed conference. The envoys will be John Graham, deputy undersecretary at the Foreign Office,and Stephen Low, U.S. ambassador to Zambia.