President Reagan said yesterday that U.S. Ambassador Charles M. Lichenstein "had the hearty approval of most people in America" when he suggested that the United States would not object if the United Nations decided to move its headquarters out of New York.

"I think the gentleman who spoke the other day had the hearty approval of most people in America in his suggestion that we weren't asking anyone to leave, but if they choose to leave, goodbye," Reagan said in response to a question during a White House luncheon with a group of editors and broadcasters.

The president, who is scheduled to speak to the U.N. General Assembly on Monday, added that U.N. Ambassador Jeane J. Kirkpatrick had "an interesting suggestion also that should be thought about. Maybe all those delegates should have six months in the United Nations' meetings in Moscow and then six months in New York, and it would give them an opportunity to see two ways of life. And we'd permit them."

Despite the comments of Lichenstein and the president, senior administration officials said they don't believe the United Nations would move from New York City.

"I don't know that there's a serious move to take the U.N. out of the country," said presidential spokesman Larry Speakes.

The issue came up after the governors of New York and New Jersey, responding to the Soviet Union's shooting down of a South Korean airliner, refused permission for Soviet Foreign Minister Andrei A. Gromyko to land at their civilian airports to attend the current U.N. session. Gromyko then canceled his trip rather than land at a U.S. military airfield.

Lichenstein, Kirkpatrick's deputy, said Monday that if U.N. members feel unwelcome in this country, "The United States strongly encourages member states to serious consider removing themselves and this organization from the soil of the United States."

Lichenstein added, "We will put no impediment in your way." Members of the U.S. Mission, he said, "will be down at dockside waving you a fond farewell as you sail into the sunset." Lichenstein, speaking at a U.N. committee on host country relations, was responding to a Soviet diplomat who had questioned whether the United States was a proper location for the U.N. headquarters.

Earlier yesterday, before Reagan spoke at the luncheon, Speakes said the United States will "meet our obligations" under the treaty establishing the U.N. headquarters in the United States. Asked whether the Reagan administration, as a matter of policy, would like the United Nations to remain, Speakes said, "Yes, sure."

Meanwhile, 24 House Democrats called yesterday for Lichenstein's resignation, saying that his comment "reflects Mr. Lichenstein's outright hostility to the goals and operations of the United Nations, and proves that he is unfit to represent our country in that body."

Reagan is expected to use the U.N. speech Monday to denounce the Soviet attack on the Korean plane on Sept. 1. Yesterday, the White House said Reagan will host a reception Sunday for heads of state and foreign ministers attending the 38th annual meeting of the General Assembly.

Soviet U.N. Ambassador Oleg Troyanvosky will not be invited because Gromyko is not attending the session.

Reagan was questioned repeatedly yesterday about the role of the American forces in Lebanon. When a reporter asked how far he would go to back the government of Lebanese President Amin Gemayel and whether American prestige is now "completely tied up in their success," Reagan said:

"We can't, obviously can't, guarantee victory."

Referring to the recent Navy shelling of Druze militia positions, Reagan said that U.S. Marines would have been in an "untenable" position had the Druze taken the crucial town of Suq al Gharb "because those who had been shooting at them will be looking right down their throats from those heights, very close."

"The mission that the multinational force was created for has not changed," Reagan said. He accused the Syrians of acting under Soviet influence in fomenting "much of what is presently going on" in Lebanon. He also charged that Palestine Liberation Organization fighters have "reinfiltrated" Lebanon after being expelled last year.

Reagan said his entire Middle East peace initiative hinges on the efforts to find a cease-fire in Lebanon. "And if this fails, the peace plan for the whole Middle East that we had proposed . . . I think also goes," he said.

On Central America, the president was asked whether the United States is "getting into a war to avoid a communist takeover" in the region.

"Now, you've asked a question that I really shouldn't answer," he said. "I don't see the necessity for the United States going to war in any place where we are . . . . " He recalled that he had said once before that "a president should never say never," then added:

"But there is nothing in our plans that envisions a war for the United States. Our job is trying to prevent war wherever it may come in the world."