Iranian Prime Minister Mohammed Ali Rajai's office yesterday publicly demanded a "positive or negative" response from Washington on Iran's four conditions for the release of the U.S. hostages and handed a message for the United States to Algerian intermediaries.

As expected, the Iranian response to the U.S. plan for meeting the conditions neither accepted nor rejected the U.S. proposals. Instead, it opened up the prospect of another round of exchanges between the two countries as they attempt through intermediaries to work out differences on how, if at all, the conditions can be met.

Iran's official Pars News Agency quoted Rajai's spokesman as insisting that Washington "clearly announce its positive or negative response" to the Iranian conditions.

Publicly, the prime minister's spokesman described the U.S. position as "neither explicit nor clear." He appeared critical that with regard to some of the Iranian conditions,"not only had a direct reply not been made, but additional proposals had been offered.

"We have asked the Americans to give a clear, precise response to the Iranian position," he said, according to news service.

Washington sources yesterday said they had no direct knowledge of what the Iranian response contained, but voiced satisfaction that Rajai appeared to be following through on his public statements Thursday that he would seek "clarifications" in the U.S. position and "give more explanation" of what his country is seeking.

The political infighting among the factions within the Iranian revolutionary government -- which up to now has prevented any single power center from emerging -- has been one reason that the Carter administration has not been able to carry out any successful negotiation for the release of the 52 hostages.

Rajai's emergence as the focal point in the current effort has been seen as a hopeful sign in Washington. Yet even yesterday's statement from Rajai's office signaled the fragile political situation.

"Since the government of the Islamic Republic of Iran considers itself to be only the executor of the Majlis [Iran's parliament] on this subject, the United States is presumptive" in modifying the conditions as approved by the parliament, Rajai said. He appeared to be assuring parliament that it could, if it wanted, have another crack at the release conditions if any changes were made.

The Carter administration, too, faces political problems about what it can do in bargaining for the hostages, who have been held more than a year. Specifics on the delivery of weapons and spare parts, which have been held up by Carter's freeze of Iranian assets, could become controversial. More certain would be difficulties on Capitol Hill for Carter or President-elect Ronald Reagan if he seeks legislation to immunize Iran from future lawsuits by the hostages or their families arising out of their imprisonment -- one of the conditions Tehran is seeking.

The Algerian intermediaries, ambassadors of their country to Tehran and Washington, are expected to return to Algiers, confer with their foreign minister and decide whether they will deliver the Iranian response to U.S. officials in Algiers or Washington.

The four conditions, enunciated by Ayatollah Ruhollah Khomeini on Sept. 12, and approved by the parliament Nov. 2, called for a U.S. pledge not to interfere with Iranian internal affairs, release of the more than $8 billion in blocked Iranian assets, removal of claims by U.S. individuals and corporations against Iran and transfer to Iran of the wealth of the former shah and his family.

Although the Iranian government has not made public the substance of its response, an example of what it might contain was suggested during a recent interview of a high Iranian government source, contacted by telephone in Tehran.

He said Iran in its response planned to ask the United States to clarify whether military equipment and spare parts that Iran has already paid for but are being held by the United States and its allies, along with other frozen assets, would be released in return for freeing the hostages.

During the presidential campaign debate Oct. 29, Carter declared that when he halted trade with Iran after the hostages were taken, "I announced then and have consistently maintained since then that if the hostages are released safely, that we would make delivery on those items which Iran owns -- which they have bought and paid for."

Although that seems to be a clear declaration of policy, officials queried at the State Department, Defense Department and even the White House in the past two days have said the president's words do not guarantee a completely positive answer to the Iranians.

One Carter aide said, "I can't forecast the response to a question that has not been raised." He added that it is worth remembering that the president's remarks were made "in the heat of the campaign."

One State Department official voiced hope that the question on military equipment is not raised because "it can only cause problems for both of us."

The U.S. response to Iran's original conditions ignored military spare parts because the statement on the conditions as approved by the Iranian parliament made no mention of them.

In Tehran, there is sharp disagreement among the still-warring revolutionary government factions about whether Iran should accept military equipment from the United Sates -- terms "the great Satan" by Khomeini who has voiced opposition to such an action. He is joined in that position by Hojatoleslam Ali Akbar Hashemi Rafsanjani, the speaker of parliament.

Rajai, however, said Thursday that the embargo on shipping the paid-for spare parts was "an important problem" that he linked to the hostages.

"Delivery of those arms in our right," the prime minister declared.

The Iranian response was also expected to seek clarification of a U.S. suggestion that the legal claims filed against Iran by American individuals and corporations could be transferred from courts to a special commission.

The Iranians are known to favor putting the claims into an international commission, perhaps chaired by an Algerian, if that route is to be taken at all.

Another issue expected to be raised is the amount of frozen funds that will immediately be made available by the United States once the hostages are released. Iran's original conditions called for "all capital of Iran . . . as well as all the assets and properties of Iran" to be made accessible "to the extent that the government of the Islamic Republic of Iran could make use of them under any circumstances which may be deemed expedient."

The military equipment, according to an Iranian official, although not mentioned specifically in the listed conditions, falls under these "assets and properties of Iran."

The Iranians, however, are far from certain just what equipment they are still entitled to.

For example, one item mentioned in the Tehran telephone inverview was a submarine initially purchased by the former shah's government.

Defense Department officials said yesterday that the sub along with billions of dollars of other weapons and spare parts purchases had been canceled in a renegotiation understanding signed Feb. 3, 1979, by a representative of the provisional revolutionary government.

According to Pentagon officials, almost $9 billion of $12 billion ordered by the shah's government was canceled by that understanding.

The Iranian official yesterday said he believed the United States was still responsible for about $2.5 billion in Iranian purchases from the Pentagon.

A Defense Department spokesman said that about $1 billion of the Iranian money has been used to pay off contacts that Iran wanted canceled. He said another $470 million in cash was being maintained in a trust fund used to pay for Iranian military purchases.

Another $550 million worth of parts and weapons, he said, would be considered material "in the pipeline," and technically availble for delivery if the hostages are released and the freeze lifted.

"Some would be applicable to their war effort," he said, "but it would not be sufficient for their needs."