Israeli Prime Minister Moshe Dayan arrived in the United States yesterday for a new round of Middle East talks after a weekend of secretive travels in Europe and a surprise return to Israel.

As Dayan flew to New York, Egyptian Foreign Minister Ismail Fahmi, also due in Washington this week, left Cairo and said there can be no Middle East settlement without the Palestine Liberation Organization.

Both Fahmi and Dayan are scheduled to meet with President Carter and Secretary of State Cyrus Vance this week. Syrian Foreign Minister Abdul Halim Khaddam will meet with Carter Sept. 28, Damascus Radio reported.

The Los Angeles Times reported from Cairo that a reliable source there said a "very respected American who is a friend of the Carter administration" has met frequently with PLO leader Yasser Arafat.

The Washington talks are expected to set the stage for indirect, Arab-Israeli negotiations mediated by Vance during the U.N. General Assembly's fall session, which opens this week in New York.

Dayan had originally planned to leave for the United States on Friday, but he abruptly changed his itinerary, flew secretly to Paris Saturday and later returned home to consult with Prime Minister Menahem Begin.

The surprise shuttling fueled rumors of possible new developments in the Middle East. Some Israeli newspapers speculated that Dayan had secretly met with a top-ranking Arab or Soviet official in Paris for talks that might affect his U.S. mission.

Fahmi left Cairo for two days of talks with French officials before he travels to Washington, where he will meet with Carter Wednesday. He denied reports that he had met with Dayan in Paris.

In an airport news conference, the Egyptian foreign minister said he was carrying a letter to Carter from President Anwar Sadat underlining the necessity for PLO participation in a reconvened Geneva Middle East peace conference.

Last week U.S. officials announced support for Palestinian participation in Arab-Israeli talks. The announcement was a "positive step," Fahmi said, "but it did not go far enough."

There will be "no chance whatsoever for a peaceful settlement" without U.S. recognition of the PLO, he said.

Washington has refused outright recognition of the PLO because the organization's charter calls for the dissolution of the Jewish state.

Israel has said it would support the inclusion of Palestinians in future peace talks but will not negotiate with members of the PLO, which it regards as a terrorist organization.

The Los Angeles Times report said the "respected American" who met with PLO leader Arafat was seeing a formula to clear the roadblocks to U.S. recognition and to PLO participation in future Geneva talks.

Meanwhile, in Washington, a group of Palestinian sympathizers released three CIA documents that they will showed that Dayan had deliverately ordered an attack on the U.S. intelligence ship Liberty during the 1967 Middle East war. Thirty-four Americans were killed in the attack, which Israel said was accidental. The American Palestine Committee obtained the documents through the Freedom of Information Act.

A CIA spokesman said the documents contained "unevaluated information." The Associated Press reported that a separate CIA study concluded that Israelis did not learn that the Liberty was an American ship until after the attack.