President Reagan said yesterday that Iran has "not been as helpful" as it could be about ending the hijacking crisis in Tehran, but added that "I have no evidence that I can lay out here that there is actual collaboration" between the Iranian government and the hijackers.

Reagan also said "we are in touch with the heads of state of the countries, and we have, through other diplomats, been as much in contact as we can be" to get help "in this whole tragic situation."

After the president's remarks at a late-morning White House news conference, State Department officials said they had picked up signs that the Iranian government was for the first time moving to resolve the crisis at the Tehran airport. This assessment was based on Iranian actions during the day and information received through diplomatic channels.

One U.S. official explained Iran's shift by saying Tehran had concluded that Kuwait was not going to bow to the hijackers' demands to release a group of pro-Iranian Shiite Moslems jailed by Kuwait as terrorist bombers. This leaves resolution of the situation up to the Iranian government, he said.

The five hijackers were linked by U.S. officials to a radical Shiite group called the Party of God, suspected of plotting the bombing last year at the Beirut International Airport in which 241 American servicement died.

There were conflicting reports as to whether the hijackers had killed four hostages or five since the confrontation began on Tuesday. They still held about 50 people yesterday, including two Americans, and were threatening to shoot some of them if their demands were not met. In a statement yesterday, the hijackers identified two Americans as among the dead.

The bloody spectacle, part of which the Iranian government has allowed to be broadcast and photographed, brought questions at yesterday's news conference about whether Reagan would order retaliation.

"Will we do anything?" one reporter asked.

"There isn't anything that I can discuss further about details in this whole tragic situation," the president replied.

An administration official said, "I see no way the U.S. military could go plunging into the Tehran airport" to rescue the hostages. The new focus of concern, he added, is whether the hijacking of the Airbus passenger liner, on a flight from Dubai in the Persian Gulf to Karachi, Pakistan, is an isolated event or the first of a string of terrorist actions by Party of God radicals.

Although Reagan could order retaliatory action by bombers on aircraft carriers in the Mediterranean and Persian Gulf region, Navy officials said yesterday there had been no changes in the readiness status of those ships. The aircraft carrier USS Eisenhower and nine accompanying warships were in the Israeli port of Haifa, and the carrier USS Independence was on patrol in the northern Arabian Sea.

The terrorists hijacked the airliner, which carried more than 150 people, shortly after it took off from Dubai, one of the United Arab Emirates. The Iranian news agency said yesterday that 107 passengers had been released and 57 people remained on board.

Although some State Department officials linked the hijackers to the Iranian-backed Party of God, department spokesman John Hughes declined to voice that connection at the department's news briefing yesterday. Hughes also seemed to step back from another department official's remark about near-collusion between the Iranian governmetn and the hijackers.

"There has not been as much dispatch or effectiveness as we would like," Hughes said. "In the past, the Iranians have proved that they are capable of acting forcefully and effectively in cases of hijacking. It is not usual in such situations to permit the hijackers access to the media, as has been done in this case. Letting a photographer on board the airplane to photograph corpses is not usual."

Robert B. Oakley, director of the department's Office for Combatting Terrorism, in an appearance Thursday night on ABC's "Nightline" program, said:

"We feel that there is a great deal of sympathy, if not support and active collusion, on the part of the Iranian government, judging from the treatment which they have given to this paticular incident."

The United States, which does not have diplomatic relations with Iran, has been working through Swiss diplomats in Tehran and has appealed to Algeria and Syria to press the terrorists to release their hostages.

Asked if the State Department believed that Iran should assault the plan, as its commandos did when a Saudi airliner was hijacked there, Hughes replied:

I'm not saying that. There are a variety of ways to deal with such situations. It is not for us to say at what stage you should assault the plane."