Four days after President Carter said Rhodesian Prime Minister Ian Smith probably would be given a visa for the United States, and one day after the State Department indicated that he would not, Smith still could not be certain yesterday whether he should pack his bags for the controversial visit.

The administration has not reached a final decision on visa applications from Smith and three black members of Rhodesia's executive council, State Department press officer Kenneth Brown said yesterday in response to a reporter's questions.

On Saturday, in response to questions from reporters, Brown said the State Department could not grant Smith a visa at this time. That position had been relayed earlier in the day to Capitol Hill supporters of the Smith visit only as "an interim decision," Brown said yesterday.

He emphasized that his statement did not mean that Smith had been refused a visa. Neither did it mean, he quickly added, that Smith would be granted a visa. It meant, he explained, that the application, submitted Sept. 20 and the subject of intense debate at State since then, was still pending.

The handling of the "interim decision" fanned suspicions by Smith supporters here that the State Department would feel more comfortable in dealing with the application after Oct. 14, when Congress is due to recess. Smith reportedly hopes to press his case in person to members of Congress.

Smith took control of the white settler government in Rhodesia and milaterally declared independence from British colonial, rule in 1965 rather than share power with the country's black majority. The United Nations declared the Smith government illegal and its travel documents invalid, and imposed economic sanctions supported by the United States.

Setbacks in Rhodesia and South Africa could imperil U.S. policy in southern Africa. Page A18

Confronted by an escalating guerrilla war, Smith brought three African nationalist politicians, Bishop Abel Musorewa, the Rev. Ndabaningi Sithole and Chief Jeremiah Chirau, into the ruling executive council in March and promised free elections that would bring majority rule by the end of the year.

The Carter administration maintains that only an agreement reached by the Smith group and the guerrillas can end the war and bring a lasting settlement. This position has come under increasing criticism from U.S. conservatives as Soviet and Cuban military help to the Patriotic Front guerrillas has increased.

The principal sponsor for the Smith visa application has been Sen. S. I. Hayakawa (R-Calif.), who had been pressing the State Department to approve a visa so that Smith and Sithold could arrive here today. Arrival dates for Muzorewa, who was reported to be balking at making the trip, and Chirau had not been set.

Meeting with reporters on Wednesday, Carter replied to a question by saying that "my guess is that the State Department would approve the visas on a tourist basis, not as a matter that would imply diplomatic recognition of Rhodesia."

While that comment revived the hopes of Smith supporters, it did not decide the issue at the State Department. "We did not receive that as an instruction," Richard M. Moose, assistant secretary of state for African affairs, said Friday. "The president was expressing a view."

Moose indicated in a conversation with Hayakawa that day that the decision probably would be reached over the weekend after Secretary of State Cyrus R. Vance returned from the United Nations. Undersecretary David D. Newsom called the senator Saturday with word that Smith would not be able to come today and that a decision on a visit would be made "in the light of developments in Southern Africa," Brown said.

Moose said the decision was "broader" than the issue of Smith's traveling on a Rhodesian passport, which the United States does not recognize. The State Department has the authority to waive that restriction.

Senior State Department officials said last week that a sharp debate had broken out at several staff meetings devoted to the Smith case, but Moose said there was no "great struggle" going on within State. Transafrica, a black U.S. lobbying group, has threatened to go to court to block the issuing of a visa if State approves one.

Brown said that the application was "under active review" and the issue should be decided fairly soon. But he said he could be more specific on timing.