An Israeli spokesman said the Cabinet took steps today that "encourage the chance for peaceful solution" to the crisis over Syrian surface-to-air missiles in Lebanon, but this optimism was clouded by sharp statements from Prime Minister Menachem Begin and Syrian President Hafez Assad.

Begin met with U.S. special negotiator Phillip C. Habib for more than two hours following the Cabinet session and Habib appeared set to continue his efforts to end the confrontation in Lebanon.

For his part, Habib said after meeting with Begin that "the diplomatic efforts will continue." He is expected to leave Israel Thursday for futher talks with Arab leaders in Damascus and Beirut. Despite the appearance of momentum given by both Begin and Habib, there were no details available on just what Habib would be carrying with him as he returns to talk with the Lebanese and Syrians.

Begin had sharp words for Assad, however, terming as "very extremist" the Syrian's statements in Damascus earlier in the day that U.S. ideas to end the three-week crisis represent, in effect, Israeli demands.

(Washington Post correspondent Stuart Auerbach reported from Damascus that Assad said there was no agreement yet on an end to the crisis and that he had not yet been given any specific U.S. proposals. He added, however, that it is still too early to say whether Habib's mission will succeed. "It is better to wait a few days," the Syrian leader said.

"It is not an exact statement, to put it mildly . . .," Begin said in reference to Assad's statement. "It doesn't prove good will to solve the problem by peaceful means. The statement made by President Assad doesn't create the proper atmosphere," Begin said.

He was talking with reporters after his session with Habib, who for two weeks has been conducting shuttle diplomacy between Damascus, Beirut and Jerusalem in an attempt to resolve the crisis arose April 28 when Israeli warplanes shot down two Syrian helicopters in central Lebanon, prompting the Syrians to deploy the missiles in response.

"The fact is, Mr. Habib brought American proposals to Mr. Assad, and I know of this. . . . But perhaps Mr. Habib will overcome this difficulty," Begin said.

Earlier today, Israeli Cabinet Secretary Areyh Naor announced that the Israeli ministers had discussed Habib's report and had "made appropiate decisions." When asked if they advanced prospects for a peaceful solution to the crisis, Naor replied, "Yes, indeed, they encourage the change for a peaceful solution."

Shortly afterward, in a meeting in the Knesset (partiament) with the Agudat Israel faction of the Likud ruling coalition, Begin was reported to have said that the Syrians had made significant concessions to Habib, and that he was optimistic that a peaceful solution could be reached.

In his comments tonight, the prime minister confused the situation somewhat, saying that no decisions had been taken by the Cabinet. "The proper authorities convened, but the proper authorities did not take proper decisions," Begin said in response to a question.

Uri Porat, the prime minister's spokesman, later said formal Cabinet decisions "were not necessary," and therefore were not made. When pressed on Naor's earlier statement, Porat talked again with Begin and declared, "The proper decision was made not to make a decision." Porat said that the Cabinet did decide, however, to give Habib more time to continue his shuttle diplomacy.

Begin, when asked whether Israel had accepted the U.S. proposals to end the impasse, replied, "We don't have to accept anything because what we said all the time was that the status quo ante must be restored. And this exactly what Mr. Habib said to the Syrians and everyone else. The status quo ante must be restored."

The "status quo ante," as Begin has defined it, is a return to the delicate balance of policy objectives in Lebanon that both Syria and Israel have maintained since a Syrian peacekeeping force entered the country in 1976 to end the civil war. It includes a "red line" beyond which Syria tacitly agreed not to pass in troop movement south toward the Israeli border, as well as prohibitions on the introduction of antiaircraft missiles by Syria.

Begin tonight vehemently denied that Israel had even been asked by Habib to reduce or restrict its overflights of Lebanon, either for reconnaissance or operational purposes: "Never has a proposal been made by anyone, including the Americans, to stop filghts that are so vital to our national security because of the murderous activities of the PLO [Palestine Liberation Organization]. We must know what's going on there, because it is necessary to defend our people."

Begin said he will insist that the Israeli Air Force have freedom of movement "every place in Lebanon," but he denied that Israel had any intent to attack Syrian positions or Syrian aircraft in the process. He characterized the attack on the helicopters and one previously reported artillery bombardment of a Syrian infantry unit in south Lebanon last year as "exceptional cases" that did not bear upon the current negotiations.

Begin also drew back, in tone at least, from his scathing attack on Saudi Arabia as a "reactionary, medieval regime . . . not capable of playing a useful role" in the negotiations. The Saudis, according to U.S. sources, are important to Habib's efforts to turn the impasse into an inter-Arab matter that can be resolved with a minimum of Israeli unvolvement.

When asked about the consequences of those comments on the negotiations, Begin replied, I don't change my mind, and I do not withdraw one word I said about Saudi Arabia and the regime. But you have to be truthful. In the last 24 hours, they tired to help, by making several proposals, by several statements in private they made -- many ways."