DURBAN, South Africa (AP) _ President P.W. Botha proposed limited talks with South Africa's neighbors and Western countries that oppose tough economic sanctions Tuesday, but said the talks would not mean ''abdication of the white man's right in his own fatherland.''

Both said the results of any negotiations would have to be approved by South Africa's voters in a referendum or national elections. South Africa's 24-million black majority does not have the right to vote.

The South African president described the international call for sanctions against South Africa as ''one of the most extreme forms of political fraud of the 20th century,'' and said sanctions would make his country stronger.

Botha addressed about 3,000 people at a seaside conference hall where his National Party gathered for a two-day congress to consider how to counter anti-apartheid sanctions from abroad and pressure from critics at home.

Among the topics to be discussed Wednesday are a proposal to continue to maintain separate schools for blacks and whites, to expand grant autonomy to blacks at the local and regional level, and to bring more blacks into government without allowing a one-man, one-vote system.

During most of his two-hour speech, given mostly in Afrikaans, Botha reiterated established government policy and endorsed the National Party's program of cautious political reform, stopping short of a one-man, one-vote system.

Botha said negotiations with the United States, Britain and West Germany as well as South Africa's neighbors could deal with regional security and economic problems.

The United States, Britain and West Germany have opposed tough economic sanctions against South Africa.

He said, however, the government would not be forced into negotiations with radical elements, a reference to calls from the Commonwealth and the European Community to lift the ban on the African National Congress, the main guerrilla group fighting to overthrow the government.

''We are irrevocably committed to dialogue as part of the process of the broadening of our participatory democratic insitutions,'' Botha said.

''Dialogue should not, however, lead to a situation where the self- determinat ion of the groups and communities in our multi-cultural country is jeopardized,'' he said. ''Therefore, if our negotiations lead to drastic changes to our country's constitution, I will keep my promise to consult the voters beforehand.''

''For the national government, negotiation does not mean abdication of the white man's rights in his own fatherland,'' he said.

Botha also said a referendum on changes in the country's constitution ''could take place sooner than most people think.'' Botha does not have to call elections until 1989.

The opposition Progressive Federal Party has suggested that the National Party may call early elections because it feels better prepared to withstand right-wing competition after Botha's government stood up to threats of international sanctions and refused demands to speed up the process of ending apartheid.

Apartheid is a system of racial segregation under which 5 million whites control the government and economy and maintain separate health and education facilties. Blacks have little say in national affairs.

''We do not desire sanctions, but if we have to suffer sanctions for the sake of maintaining freedom, justice and order, we will survive them. Not only will we survive them, we will emerge stronger on the other side,'' Botha said.

Referring to international criticism of the South African government, Botha said: ''We are probably no better, but certainly no worse than the rest of the world.''

''In the West, we in authority here, and our evolving South African order are often presented as worse than the Soviet Union,'' Botha said. ''But in the same Western quarters we find a general tolerance of the Berlin Wall, and the communist tyranny over Poland, Afghanistan and other countries in Eastern Europe.''

Botha put forward one new proposal, saying that black urban communities close to the major cities could receive full autonomy as city-states.

He touted the 10 tribal homelands - four of them considered independent states by the government but not recognized by other nations - as examples of expanding freedom and distribution of self-government to blacks.