Rhodesian Prime Minister Ian Smith yesterday publicly stated for the first time what he has been telling closed meetings of whites from in Rhodesia: That he will retire from public life when a black majority government takes over.

"I have been a controversial figure - let's not beat about the bush," said the 59-year-old farmer-turned-politician in Cape Town yesterday where he is on vacation. "I have no intention of standing in the next elections. By then my task will have been completed and I will have done all I can to reassure the people of Rhodesia."

Elections for a black majority government are scheduled for the end of this year under the Salisbury agreement Smith signed March 3 with three moderate black leaders based inside Rhodesia.

Smith's public announcement that he does not intend to participate in the new government removes one of the principal objections to the agreement by black guerilla leaders and their African backers who oppose the so-called "internal settlement."

Zambian President Kenneth Kaunda, who supports guerilla leader Joshua Nkomo and his estimated 8,000 troops, has called upon the United States and Britian on numerous occasions to force Smith to step down. Smith has ruled Rhodesia since it declared its independence unilaterally from Britain in 1965.

Smith, who met yesterday for two hours with South African Prime Minister John Vorster also said he saw indications that Zambia, Mozambique, the United States and Britain were "moving towards a reassessment of the internal settlement." Both Britain and the United States have refused to endorse the Salisbury agreement because it does not include guerilla leaders Nkomo and Robert Mugabe, who lives in Mozambique.

Britain's Labor government has been under pressure from the Conservative Party to give more support to Smith and the three internal leaders, Rev. Ndabaningi Sithole, Bishop Abel Muzorewa and Chief Jeremiah Chirau. If Britain holds elections in the fall, Conservative Party gains or a victory could possibly swing the British government fully behind the internal settlement.

Smith also countered widespread skepticism in Rhodesia that there is not enough time to hold elections before the agreed date of Dec. 31 when Rhodesia is to be turned over to a black majority government.

"We have a good chance of complying with the date set down in the agreement and that is the intention of all of us," he said.

[Reuter reported from Salisbury yesterday that guerillas attacked Chief Chirau's home on Wednesday night but there were no casualties. The chief was away from his house at the time and a spokesman said minimal damage was caused.]

[The government also announced yesterday that three more white farmers were killed by guerillas in a 24-hour period, bringing Rhodesia's announced white civilian death toll for the year to 46.]