Special U.S. envoy Robert Strauss held an unexpected meeting at the U.S. consulate in Jerusalem tonight with Elias Freij, the Palestinian mayor of Bethlehem who has been a vocal opponent of the Camp David peace agreements.

The 40-minute meeting was Strauss' first with a Palestinian leader within Israel or the occupied West Bank, although he has met with Palestinians in Washington. It underscored his often declared intention to make and maintain contacts with Palestinians about the West Bank autonomy talks despite Israeli sensitivites on the subject.

Strauss made light of the meeting's importance, saying Freij "is the only fellow I found on the West Bank who said a kind word about me." The discussion nevertheless demonstrated changing Israeli attitudes toward contact between American officials and militant West Bank leaders.

Jerusalem protested strongly last year when the assistant secretary of state for Near Eastern and South Asisan affairs, Harold Saunders, met here with several West Bank leaders, including Freij. But Israel was hardly in a position to protest this time, since Foreign Minister Moshe Dayan has met eight times with West Bank and Gaza Strip leaders since the Egyptian-Israeli peace treaty was signed March 26, including open supporters of the Palestine Liberation Organization.

"We just had a very nice discussion," Strauss said in briefing reporters after the meeting.

He added that the conversation included talk about Freij's proposal for a federation between Jordan and an independent Palestinian state on the West Bank and in Gaza. He was reluctant to go into more detail, however, apparently because of Israeli concern about the Palestinian issue.

Strauss said he had informed Prime Minister Menachem Begin of his intention to see Freij at a meeting with the Israeli leader immediately before he drove to the consulate to talk with the Bethlehem mayor. Begin raised no objections, Strauss said.

Prior to the Camp David summit, Freij was regarded by the Israeli government as one of the most moderate mayors in the West Bank. But he hardened his position dramatically last fall and became one of the treaty's most outspoken critics, often predicting that not one Palestinian political figure would participate in the autonomy talks.

Earlier today, Freij, a Christian who was reflected mayor of Bethlehem in 1976, offered reporters details of his proposal for a federaion between Jordan and a Palestinian state.

"I don't think the people will really accept [autonomy], but they would accept a federation with Jordan.Jordan and the West Bank complement each other," said Freji, who has maintained close ties to Amman since Jordan lost control of the West Bank in the 1967 six-day war.

Freij described the bi-state proposal as "two lungs in one body," with a central parliament, one army, one police force, one currency and one passport. "But the Palestinian state would function properly by itself, and Jordan would function properly by itself," Freiji added.

PLO leader Yasser Arafat has said he would consider relations with Jordan only after Palestinians have an independent state as a platform to deal from. King Hussein, the Jordanian monarch, also has officially supported the idea of an independent Palestinian state since the Arab summit conference of 1974. The idea of some kind of federation is known to enjoy some support, however, among the king's backers in Amman.

Strauss said that U.S. Consul-Genearl Michael Newlin was the only other person present in his meeting with Freij and that no other West Bank leaders had been invited. He did not specify whether any other West Bank figures had been sounded out about possible invitations.

After his 90-minute talk with Begin in the Prime Minister's office, Strauss said he felt it is important at the Egyptian-Israeli talks on the Palestinian issue seek progress on specific issues dealings with the election of a Palestinian self-governing council and then deal with the larger issues concernings its powers and source of authority.

Of the unhurried negotiating schedule that both Egypt and Israel seem to have accepted, Strauss said, "I think we have finally started out on a timetable we are all comfortable with."

The special ambassador said that about a third of his meetings with Begin focused on the situation in southern Lebanon, but not in the context of the effect of Israel's support of Christian militias there on the autonomy negotiations.

Several weeks ago in Washington, however, when the shelling in southern Lebanon was intense, Strauss expressed fear that the violence there could harm his efforts in the autonomy negotiations.

Today Strauss said Begin spoke at length and "eloquently" on the "tragedy of Lebanon," and that I complimented them on the restraint of the past 13 days."