Secretary of State George P. Shultz yesterday welcomed Israel's careful apology for "spying on the United States . . . to the extent it did take place," and U.S. supporters of Israel expressed relief that the government in Jerusalem had moved to improve a deteriorating situation.

Shultz said, "I think this is an excellent statement, and we are satisfied by it, and we welcome it. We have full confidence in Israel's determination and ability to pursue this case down to the last detail and to bring those responsible to account."

Shultz spoke to reporters traveling with him to Colombia for a meeting of the Organization of American States. Some of his comments were made available by the State Department here.

A major issue in addition to Jonathan Jay Pollard's alleged espionage activities against the United States on behalf of Israel was the sudden recall to Israel last week of two diplomats reportedly involved in the affair.

According to Reuter news service, Shultz told reporters, "We have been assured that the Israelis will provide us with access to the individuals who are knowledgeable about the case and that Israel will give us a full report on the extent of whatever activities their investigation reveals to have taken place."

A State Department spokesman here confirmed the thrust of that statement.

Israeli Prime Minister Shimon Peres' apology, in a statement to the Israeli cabinet, did not mention making anyone available to U.S. investigators.

However, Assistant Attorney General Stephen S. Trott said on NBC News' "Meet the Press" yesterday, "We will take the Israelis at their word, but the proof will be in the pudding. We intend to consider this an invitation to participate in the investigation." He also said, "Without getting into the details, we like to look at people in the eye in order to assess the information that they give us."

President Reagan was asked by reporters as he alighted from his helicopter in Santa Monica, Calif., if he was satisfied with the apology. He did not reply.

Hyman Bookbinder, Washington representative of the American Jewish Committee, was among Israel's friends here who was relieved. "I was very pleased that they went public with a statement of apology . . . . I hope that this is the beginning of the easing of the situation."

Bookbinder said, "We had reason to be concerned about the reaction of Americans to this. But now , a friend has acknowledged a mistake and says it will not happen again. In this better frame of mind, I hope Americans will remember this relationship has been useful to both countries."

Sen. Daniel Patrick Moynihan (D-N.Y.) said on ABC News' "This Week With David Brinkley," "I think we should be alarmed" about the spate of reported espionage cases. "I think we should start pulling out fingernails to make clear it's not funny, not worth it and it won't be tolerated."

However, he said, when it comes to Israel, "they've offered us a very handsome apology. We can straighten this out in no time." He also said, "This is a time for the people who are friends of Israel to say nothing is going to change that relationship of ours, but that relationship involves an agreement to do what they've just done, to get those documents back and to give us access to those two people."

Moynihan represents a large Jewish constituency and has been a staunch friend of Israel on Capitol Hill.

Richard Helms, former director of the Central Intelligence Agency, put the issue in the context of the intelligence community's view when he said on the same program, "The issue is that since this is an illegal activity to begin with -- and espionage has always been illegal since the beginning of time -- countries do it, they try not to get caught, if they do get caught then that's bad. But if they don't get caught, it's a fine thing, and the people that run these agents enjoy it."

He also said that "friendly countries spy on friendly countries," a point Israeli apologists attempted to make last week as the furor rose.