Carter administration officials expressed cautious optimism yesterday that Iran may release the 52 American hostages soon, saying that the next several days of decision-making in Tehran are likely to be crucial.

The officials, who insisted that there is no agreement yet between the United States and Iran on the hostages' release, were waiting for news of the positions that have been adopted by a seven-man commission of the Iranian Majlis, or parliament, charged with setting the terms for the Americans' release.

Reports from Tehran indicated that the recommendations of the commission will be distributed to all members of the 270-person parliament before a debate on the hostage question that is expected this weekend. Officials said that as of late yesterday the United States had not received a report on the commission's recommendations through diplomatic or other channels.

Officials have been saying for more than a week that the war with Iraq seems to have given new impetus to a drive in Iran for settlement of the hostage issue. This view has been reinforced by developments in the past several days at the United Nations, where the Security Council held a public session late yesterday on the war.

On Tuesday Iranian officials at the United Nations made known a three-point program for a negotiated resolution of the war with Iraq, with the world body playing a central role. According to sources at the United Nations, the Iranian plan provides for an Iraqi withdrawal from Iranian territory, a cease-fire, and U.N. mediation activities and observors at the Iran-Iraq border.

Intense behind-the-scenes diplomatic activity in New York has aimed at fleshing out the general and imprecise Iranian ideas in ways that might be accepted by Iraq. The meeting of the U.N. Security Council yesterday was part of the diplomatic maneuvering.

Ambassador Donald F. McHenry, speaking for the United States, said the Security Council "must work vigorously to assist Iran and Iraq to achieve a cease-fire, to begin withdrawal and to initiate a process of negotiation in a manner acceptable to both." While saying the United States "will not take sides," McHenry seemed to be continuing the U.S. support for Iran's position.

While no negotiated resolution of the Iran-Iraq war is immediately in sight in these negotiations, U.S. officials believe that Iran's willingness to involve the United Nations is an additional argument for the release of the hostages. This is because Iran will be hardpressed to enlist the aid of the world body while defying both the United Nations and the universal tenets of diplomatic practice by continuing to hold the Americans.

The U.N. visit of Iranian Prime Minister Mohammed Ali Rajai late last week was the first sign that Iran was willing to take its case on the war to the international community. However, Rajai derided a U.N. role in a settlement of the war, saying that U.N. resolutions had proved meaningless or ineffective on other occasions.

Iran's bid to involve the United Nations developed after Rajai had left for home, and after Secretary of State Edmund S. Muskie last Monday outlined U.S. general principles for a settlement of the Persian Gulf conflict. While there continues to be uncertainty that Iranian diplomats at the United Nations -- or anyplace else -- speak for all the powers back home, officials at the United Nations are proceeding on the belief that the new Iranian feelers were authorized from Tehran.

U.S. officials continued to caution that the timing of a hostage release remains very chancy, even if their reading of the mood in Tehran is correct in suggesting that the hostage saga is headed toward a resolution.

For example, a decision by the Majlis to authorize release of the Americans, even if the specified terms are acceptable to the United States, might not be self-enforcing. Therefore some authority in Tehran would have to certify that the terms had been met and implement the release.

In the last analysis, this probably would involve personal decision and action by Ayatollah Ruhollah Khomeini, who has been silent on hostage questions in recent weeks. His position is, as usual, uncertain.

The reports from Tehran that the Majlis session on the hostage issue will be public caused some concern among U.S. policymakers who took the view that a private meeting might be more conducive to a businesslike and relatively moderate result.

Nonetheless, the belief among officials dealing with the hostage problem at the White House and the State Department was that a fairly broad consensus among the various powerful factions in Tehran now favors release of the Americans in the near future.

Former secretary of state Henry A. Kissinger, speaking to reporters at a breakfast meeting yesterday, expressed a greater degree of certainty about the hostages' release than have most informed administration officials. Kissinger said that he expects the Americans to be released "in the relatively near future" because they have served the purposes their captors had in mind when they were seized last Novemeber. Kissinger would not predict whether the release would occur before or after the Nov. 4 U.S. presidential election.

Kissinger, who recently has been advising and appearing with Republican presidential nominee Ronald Reagan, emphasized that the release, when and if it comes, will be due not to the diplomacy of the Carter administration but to the internal requirements of Iran.

In Kissinger's view, the hostages were seized essentially to enhance the position of their radical captors in the post-revolutionary internal politics of Iran, and to demonstrate the weakness of the United States within Iran. A lesser objective, he said, was to weaken the U.S. position in the Persian Gulf.

Kissinger said the first two objectives were achieved several months ago. The war with Iraq, which began Sept. 22, impelled the Iranians finally to face decisions about the practicalities of the Americans' release in his view. f

In a related development, the State Department confirmed yesterday that Mohi Sobhani, 44, an American citizen of Iranian extraction, was arrested in Tehran Sept. 7 and remains in custody there. The Swiss Embassy, which represents U.S. interests in Tehran, has been seeking consular contact with Sobhani, so far unsuccessfully, the State Department said. Spokeman John Trattner said the charges against Sobhani are unknown.