UNITED NATIONS, OCT. 19 -- U.N. Secretary General Javier Perez de Cuellar said today that he was not prepared to send a team to Israel to investigate last week's bloody clash on Jerusalem's Temple Mount because of the Israeli government's opposition to the mission.

But he held open the possibility of sending a delegation later, should Western countries persuade Israel to change its stance.

"I cannot send a mission if I am not persuaded that the mission will get all the necessary facilities in order to complete their mission," Perez de Cuellar told reporters after informing the U.N. Security Council of his conclusions. "My impression is that some members of the council and some countries would like to exert some influence on Israel in order {that} they end up accepting the mission." He did not name the countries but they are thought to include the United States, Britain and Canada, among others.

But it appeared that Israel's attitude to the mission may in fact have hardened. A U.N. official who did not want to be identified said an Israeli offer to allow the mission to visit as tourists had been rescinded. "The Israelis have told us there can be no mission, not even as tourists," the official said.

Perez de Cuellar met on Thursday with Israeli Ambassador Johanan Bein, who afterward told reporters that "we agreed to cooperate in trying to find ways and means to facilitate the secretary general to write his report and present it." Bein refused to explain what he meant, but his remarks made no mention of accepting a mission.

The Security Council on Oct. 13 unanimously passed a resolution condemning Israel's actions in the deaths of at least 19 Palestinians during clashes between police and demonstrators Oct. 8 on the Temple Mount. The site is sacred to Jews and to Moslems, who call it the Haram Sharif, or Noble Sanctuary. The Security Council authorized the secretary general to send a fact-finding mission and to report back by Oct. 24.

After hearing Perez de Cuellar's comments today, diplomats representing the seven nonaligned countries on the Security Council met to consider a resolution that would deplore the refusal of the Israeli government to receive the mission and urge it to reconsider. They adjourned before reaching agreement, however, and are scheduled to resume discussions Monday. Ambassadors from Western nations were said to prefer a milder statement.

"There's some time yet to deal with this question. We hope it's going to be dealt with constructively and not cataclysmically," U.S. Ambassador Thomas Pickering said today before entering the council chamber. Pickering also described as "constructive" an offer to have the Israelis provide the secretary general with a copy of a report it is preparing on the Palestinians' deaths.

Perez de Cuellar indicated that while he had "great respect" for the Israeli report, "I cannot make a report on the basis of what the Israeli mission going to conclude.

"What I have to do is present to the council a totally independent report based on the information the mission would be able to gather," he said.