Israel's new prime minister, making his first visit to the United States since his election in May, yesterday left open the prospect of a Palestinian state but ruled out allowing Palestinian refugees to return to Israel proper or giving up part of Jerusalem.

In an interview on NBC's "Meet the Press," Ehud Barak also said he wants the United States to remain both an "ally" of his country and "an honest broker sensitive to the needs of the Arabs" in peace negotiations.

The Labor Party leader, a former army commando and general who has pledged to pursue peace more effectively than his predecessor Binyamin Netanyahu, made the comments before flying to Washington for cocktails with President Clinton and the first lady, followed by a Sunday night White House dinner and reception. He is scheduled today and Tuesday to meet again with Clinton, confer with Cabinet officials, attend a luncheon reception hosted by Vice President Gore and brief congressional leaders.

In a meeting in New York yesterday morning with U.S. Jewish leaders, Barak said he stands for "a united Jerusalem" under Israeli control and opposes returning to the state's pre-1967 borders. But he indicated that some isolated Israeli settlements in territory that Israel captured in the 1967 war would have to be dismantled as part of his plan to maintain "blocks" of settlements.

"He put a great deal of emphasis on security," said Malcolm Hoenlein, vice chairman of the Conference of Presidents of Major American Jewish Organizations, which represents 54 national Jewish groups. "He said he's going to be careful but tenacious in proceeding."

Asked on "Meet the Press" whether he believed there would be "a true Palestinian state" one day, Barak replied, "I'm not a prophet. . . . I'm focused on the security of our state, and I'm confident that the time is right . . . to strengthen Israel through peace with all its neighbors." He added, "When the time comes, the Palestinians will have to negotiate with us what kind of entity is shaped for them in a wider context of all the other issues that are on the table."

However, responding to Clinton's recent comment that Palestinians should be "free to live wherever they like," Barak said, "I don't think that refugees will be able, under any circumstances, to come back into Israel." It would be better, he said, "if a solution for them should be found in the context where they are living now."

He also rejected the idea of turning over part of Jerusalem to Palestinian control. "A united sovereign Jerusalem is our capital, and will remain so forever," he said. But he did not rule out creating a Palestinian capital in the town of Abu Dis, on the outskirts of what is now Jerusalem. Asked whether the holy city's boundaries could be extended, he said, "I don't think that it would be appropriate for us to run the very delicate negotiations that we have to run with the Palestinians here on camera on NBC."

Barak, who has pledged to pull Israeli forces out of southern Lebanon within a year, said he expects to know within 15 months whether permanent peace could be achieved with the Palestinians, Syrians and Lebanese.

"I was not afraid to fight wars," he said. "I am not afraid to make peace."

CAPTION: Israeli Prime Minister Ehud Barak greets Cardinal John O'Connor at New York home of Israeli consul general Shmuel Sisso, second from right. Next to the premier are his wife, Nava, and Rep. Jerrold Nadler (D-N.Y.).