Upset by persistent public reports of conflict between the White House and the State Department over his foreign policy, President Carter has ordered top-ranking State Department officials to silence dissent that could spill over into public view, according to administration sources.

The order was cloaked in highly diplomatic terms used by the president at a closed-door White House meeting on Tuesday, the sources said. But none of those present mistook the meaning of his demand for the wholehearted support of the State Department in carrying out his policies.

The 15-minute meeting appeared to some of those present to reflect growing White House concern that reports of serious policy differences between Secretary of State Cyrus R. Vance and National Security Affairs Adviser Zbigniew Brzezinski are creating the image of an administration that is divided and indecisive on foreign affairs, according to one account based on reports of the meeting.

Vance was present at the meeting which included assistant secretaries of state and other officials of an equivalent or higher rank. Brzezinski was not there.

The president specifically touched on his concern over public disclosures about decisions and discussions within the administration on U.S. policy toward Iran over the past three months, meeting participants said.

His remarks reportedly echoed the orders issued last month by State Department Undersecretary David D. Newsom to members of the working group on Iran, who were told not to discuss U.S. policy on Iran with reporters and to tell Newsom of any discussions they had with reporters on conditions in Iran itself.

But the president and Brzezinski are reportedly also angry and concerned about disclosures of bitter policy disputes between the White House and State Department over conventional and strategic arms limitations negotiations with the Soviet Union.

Brzezinski has repeatedly drawn the dangers of Soviet power and the need for strong American responses to that power in terms far more stark than those used by Vance and his top aides. Brzezinski is known to have complained bitterly within the confines of the White House staff about leaks from Vance aides that have been unfavorable to the national security adviser.

One participant said that in the demand for loyalty to his policies, the president did not single anyone out for blame or special attention. The brief "pep talk" was not an unexpected move at this point in the administration, the source said.

But even the existence of the meeting appeared to have been a tightly held secret. Asked for comment, State Department spokesman Hodding Carter at first refused to admit that the meeting had taken place and offered no comment on questions.

But following a brief delay, Hodding Carter telephoned with a statement that had apparently been approved at a higher level.

At a meeting of ranking department officials Tuesday, "The president discussed the policy process and did ask our help and cooperation both in implementing these policies and in discussing them," Carter said:

He declined to list the participants in the meeting, and said he did not know if top officials from any other department had been invited to the White House for similiar briefings.

Told of the meeting called by the president, other officials interpreted it as a strengthening of Brzezinski's position in defining the limits of public discussion of administration policy, which he feels has been conducted too laxly.

These officials feel that Vance is not likely to fight on the issue, which to some extent centers on pledges President Carter made when seeking the presidency in 1976 to conduct foreign affairs more openly than the Nixon and Ford administrations.

These officials cautioned against overstating the differences between Vance and Brzezinski, who tend to disagree over tactics in dealing with the Russians but who do not appear to have fundamental policy disagreements on that issue.

But the surfacing of divergent viewpoints held by the two foreign policy advisers in recent weeks has provoked sharp reaction at the White House. Brzezinski and media adviser Jerry Rafshoon are reportedly worried that Carter's public image is suffering from the appearance of squabbles in the administration.

At a January press conference, Vance pushed those differences farther into public view than he had previously by implicitly rejecting a domino theory for the political crises of South Asia, the Middle East and the Horn of Africa.

Brzezinski had earlier referred to those areas in terms that suggested a closely interrelated "zone of instability" in which foreign intervention was a key factor.

Later in January, some reporters compared speeches given by Brzezinski and Vance on relations with the Soviet Union and China and reported major differences in their approaches. White House press secretary Jody Powell ridiculed one such story at briefing, and Hodding Carter strongly denied at the State Department that any such difference existed.

But Brzezinski is known to feel that he has no serious differences with Vance and that all of his problems are with a few of the secretary's assistants.