Britain and the Netherlands have expressed an interest in contributing troops to the multinational contingent of American, French and Italian forces preparing to take up positions in and around West Beirut, according to U.S. government officials.

The first public indication of Dutch and British interest came yesterday from Defense Secretary Caspar W. Weinberger, who told a news conference in St. Paul, Minn., that "two or three other countries have expressed some interest" in sending troops to Lebanon.

Although Weinberger declined to identify the countries, other officials said that the Dutch and British governments had indicated an interest in eventually joining the operation.

Another senior administration official, speaking with reporters on the condition that he not be identified, said the United States expects that Israeli troops will be withdrawn, at least from West Beirut, by Sunday, when American Marines are to land.

Although the official reiterated that President Reagan's call for immediate Israeli withdrawal applies to the entire city of Beirut, his reference to a Sunday pullout appeared to mean only West Beirut, and not the predominantly Christian eastern half of the city.

Referring to the prospects for progress on Reagan's broader Mideast peace initiative, the senior official said the administration believes there is "a very good chance" that Jordan's King Hussein will win sufficient backing from other Arab governments and the Palestinian community to join the broadened peace process sought by the United States.

The official would not elaborate. But he said Reagan's initiative is drawing a lot of "positive interest" in the Arab world, and added:

"I think that out of this will emerge a feeling on King Hussein's part that he could enter the peace process in such a way that he won't feel isolated."

U.N. Ambassador Jeane J. Kirkpatrick, one of the staunchest pro-Israeli figures in the administration, said yesterday that the United States must share part of the blame for the massacre of Palestinian civilians in Beirut last week.

Calling for a "dispassionate, competent commission of inquiry," she said that, in addition to those who actually did the killing, moral responsibility rests with "all those who did not do everything they could to maintain order and security."

That, Kirkpatrick contended, includes not only the governments of Israel and Lebanon, but also the United States, France and Italy, which withdrew their forces from Beirut before the massacre.

In regard to broadening the multinational force, American officials said that, at the moment, the initial contingent of roughly 3,000 U.S., French and Italian troops probably will be sufficient.

Troop contributions from other countries, however, could become important if the mission or territory of the force expands, or if a long stay in Lebanon requires replacements, they said.

In addition, troops from other countries could enhance the force's mission of calming fears among Beirut's population, of ensuring that Israeli troops do not return to the city, and of giving the fledgling Lebanese government time to assert its sovereignty over the city.

With the initial group of French troops already in West Beirut yesterday, there were still unresolved differences with the Israeli government over the terms of Israel's military withdrawal from the city.

The main sticking points involve Israel's desire to retain the right to maintain a small military presence in Beirut and to send patrols into the city if necessary. The Israelis are also said to want continued use of the Beirut airport, which they occupy.

Washington does not want Israeli troops crossing the lines of the multinational force, and it wants control of the airport, which it sees as essential for getting it back into operation and for resupplying the tri-nation force.

Most importantly, administration officials said that Israel must be totally out of Beirut if the Lebanese government is to reassert control of its capital, in both a real and a psychological sense.

American officials said that the negotiations on these points are delicate because the United States does not want to put more pressure on Israel and the Israelis do not want to be seen as moving out under pressure.

But one official here said that if the Israelis cling to these two positions it will "create a real problem" once again in U.S.-Israeli relations.

Weinberger, in an interview with the Hearst newspapers, said of Israel's insistence on the right to send patrols back into Beirut:

"I wouldn't think that would be satisfactory at all because withdrawal means withdrawal, and armed patrols are not symptoms of withdrawal. The presence of such armed Israeli bands are potential problems and could easily spark a renewal of violence."

In St. Paul, Weinberger indicated that the Marines would stay on the outskirts of Beirut and said "we will not be patrolling inside" the city.

He indicated that the American force, initially set at about 800 men, could grow to 1,200, although that decision has not been made, the Pentagon said.

At the moment, officials said it is most likely that the Marines will maintain a line on the southern outskirts of the city, running roughly from the presidential palace to the airport, with Israeli forces withdrawn into the hills farther south as a first step.

Weinberger is seen as welcoming the possibility that other nations may join the multinational force. Officials said he has been the most wary member of the administration about committing American units to Beirut, both during the withdrawal of Palestinian forces last month and now during the Israeli pullback.

Weinberger, officials said, would have preferred a solution in which American and other forces were added to the U.N. troops already in southern Lebanon under an expanded charter for the U.N. contingent, known as UNIFIL.

The other senior official, talking about the post-Beirut problem of getting Israeli and Syrian forces to withdraw from all of Lebanon, said the administration envisions a possible role for UNIFIL, perhaps with its mandate and powers expanded, in meeting Israel's concern that its northern border be secure against further attacks from southern Lebanon.

When Israel invaded Lebanon on June 6 to begin its drive against Palestine Liberation Organization guerrillas, its announced goal was to create a 25-mile buffer zone in southern Lebanon. U.S. officials began working on a plan for UNIFIL to oversee such a zone, but the idea was made moot when Israel advanced to Beirut.

Asked about the strains in U.S.-Israeli relations, the official contended that ties between the two countries remain "relatively strong."

He cited, as an example of American support, an incident yesterday in which the United States walked out of a meeting of the International Atomic Energy Commission to protest an Arab-inspired vote to bar Israel by refusing to accept its credentials.