The Israeli government last night signaled its willingness to go along with a U.N. Security Council resolution calling for withdrawal of Israel forces that no occupy a large chunk of southern Lebanon and their replacement with a U.N. peacekeeping force.

The Israelis have little confidence, however, that the U.N. troops can keep Palestinian guerrillas from filtering back into the area and are unhappy over the Carter administration role in speeding the resolution through the council. They warned that they might take matters into their own hands again if necessary.

Defense Minister Ezer Weizman, in the first official reaction since the council vote, said he "hoped" there would not be any circumstances in which Israel would refuse to comply with the U.N. resolution.

Well-placed Israeli officials said privately that Jerusalem was resigned to the fact that it would have to withdraw without the kind of agreement it really wanted. The Israelis want to preserve the results of their military campaign through bargaining over the conditions of their withdrawal, however.

Weizman's press conference here coincided with the arrival in Washington yesterday of Israeli Prime minister Menachem Begin for talks with President Carter today. Begin made no public statements. (Story, Page A15).

"The Israeli government," Weizman said during his press conference, "has absolutely no interest in staying in southern Lebanon. We want to get out of there as soon as possible. But we will not again let southern Lebanon be a base of destruction against Israel."

The Israelis will try to use their power in the area to try to negotiate terms of a withdrawal which, Weizman said, must be one in which there is "no vacuum" between the departure of Israeli troops and the arrival of U.N. forces that will draw in destructure forces."

Now that they have signaled that they accept the withdrawal in principle, the Israelis are hoping for a more sympathetic ear in the White House to enforce the security provisions of the U.N. resolution.

The White House is said to be pressing the Israelis to being withdrawing within a week or 10 days, and some Israeli officials hint that a token initial withdrawal might start, "in a matter of days." But the general expectation is that it will take a few weeks to actually get the 4,000-man U.N. force organized and into positions, and that the Israeli pullout will be gradual.

Weizman met yesterday with Gen. ENsio Silasvuo, commander of U.N. forces in the Middle East, to begin mapping out plans. The U.N. commander will fly to Beirut today for initial discussions with Lebanese government officials.

Silasvuo said later that there will be a "small, symbolic U.N. presence" arriving in the area today but also suggested there were many technicalities to be solved before large numbers of troops were in place.

Israeli, in pressing for guarantees that its security to be protected, wants U.N. forces to patrol along the southern rim of the Litani River and for these troops to be backed up by Lebanese Christian militia - who have been battling the Palestinians for two years - and by Lebanese army troops further south.

The Israelis have pushed the Palestinians north of the Litani, where a 30,000-man Syrian army is also based, and they do not want them to be able to move south again to put their artillery and rockets within range of Israeli settlements.

The Israelis have stressed their protective role over the Labenese Christians. When Begin meets Carter today, one of the points Begin is expected to raise is to caution the president that without more than a U.N. force to maintain security, the Lebanese Christians may be exposed to strong reprisals from the guerrillas.

The action that triggered along standing Israeli plan to sweep the guerrillas out of their bases was the killing in Israel last week of 36 civilians by Palestinian raiders.

A statement by the Israeli Cabinet yesterday also officially pointed out that the invasion had been mounted to eradicate the nests of terrorists who had sown death and destruction among Israeli and Lebanese civilian populations alike."

Any settlement must insure . . . the well-being of citizens of Israel and residents of southern Lebanon the statement said.

The Israelis would have preferred an agreement between Israel, the Lebanese government, the Christian forces and the Syrians as the major "inter-Arab force" in Lebanon to halt the terrorism, with the United Nations policing that agreement.

Meanwhile, Weizman said there was no cease-fire in a real sense since "it takes two to have a halt." He said the Palestinians were continuing sporadic shelling from guns north of the Litany River. he said, however, that the Israeli military operations had stopped except for mopping up remaining pockets of resistance. That action was very light, he said.

Chief of Staff Mordechai Gur said 18 Israeli soldiers had been killed in the fighting out of an armored force that has been unofficially estimated at some 25,000 men. He said there were 250 known Palestinian guerrillas killed and estimated the actual casualties at about 400.

Lebanese authorities in Beirut reported that a total of 1,168 Lebanese and Palestinians had been killed since the Israelis mounted their push into Lebanon. The PLO said Sunday 144 of its forces had been killed.

Asked about these reports, Gur said he assumed there might be some civilian dead but he would not believe Arab figures. He said it would take days to find out the toll.

Gur said Israel had invited the tens of thousands of residents who had fled the south to return to their homes.

In one sense, the U.N. resolution gives the Israelis an "honorable excuse," as the opposition party newspaper put it yesterday, for getting out of Lebanon without the Arab agreement - which they were unlikely to get from the Syrians. But it has worsened the relationship with the Carter White House.

"The president should have given Begin a chance to look reasonable," said one top official here, referring to the U.S. effort to get the resolution passed before Begin arrived for his meetings with Carter.

"By ramming it through, Carter made it appear that Israel would not have withdrawn if it had not been for the U.N. resolution, which was not true."

"I don't feel Carter was acting in bad faith, but rather it seems that all they are looking for these days are for some scores in foreign policy."

A Foreign Ministry official said that Israel now had very little leeway anywhere. "The U.S. "used to be our protection from the UN."

There was also particular bitterness here toward the Vatican condemnation of the Israeli action whereas there was no Vatican condemnation of the Palestinian attacks on Lebanese Christians.