NEW YORK — Once a pariah at the United Nations, Israel is now at the center of a diplomatic flurry during the world body's 50th anniversary, which saw Israeli Prime Minister Yitzhak Rabin and American Jewish groups advancing Israel's stature at the unprecedented convergence of more than 140 heads of state or governments.

"Today one feels in the U.N.'s hallways a changed relationship to Israel on the part of many new and old members," Rabin said.

Rabin held bilateral meetings with leaders of Jordan, Qatar, China, Argentina, Brazil, Spain, Belarus, Austria, Hungary, Azerbaijan, Costa Rica and Turkey, among others.

"The list of countries reflects global representation, signifying we are definitely in the mainstream of the world community, which is where we should be," said Avner Tavori, press secretary for Israel's Permanent Mission to the United Nations. "We are no longer an outcast."

Rabin focused on campaigning for support for the peace process during his meetings, Tavori said.

"He explained regional economic development is key to the success of the peace process," said Tavori.

Rabin encouraged the wealthier countries to participate in next week's Middle East economic development conference in Amman, Jordan, he added.

In his meeting with Chinese President Jiang Zemin, Rabin was also told talks between Iran and Beijing over nuclear reactor sales have been halted and that nuclear reactors threatening Israel will not be built in Iran, according to Israeli sources.

Zemin also reportedly said China would require Iran to commit itself to refrain from transferring nuclear information or devices to third parties.

In another meeting, Costa Rica's President Jose Figueres assured Rabin that his country would not bow to pressure to move its embassy from Jerusalem, sources said.

The anniversary celebration also offered Palestine Liberation Organization Chairman Yasser Arafat the chance to return to the United Nations after a 21-year absence to trumpet and consolidate his political gains after signing the 1993 Palestinian self-rule accord with Israel.

Whereas in 1974 he boasted of bearing both an olive branch and a freedom-fighter's gun, this time he spoke only of the olive branch.

"I come to you with a heart filled with love and peace, with the olive branch hoisted over the peace of the brave," he said.

Arafat also called for economic aid to the Palestinians.

While prominent American Jewish leaders met publicly with Arafat at a meeting of the National Jewish Community Relations Advisory Council on Monday afternoon, that evening Arafat was ousted from a city-sponsored New York Philharmonic concert at Lincoln Center at the request of Mayor Rudolph Giuliani, sources reported.

For some Jews, the U.N. celebration was marred by the failure to include a specific reference to the Holocaust in a special resolution passed by the General Assembly last week marking the 50th anniversary of the end of World War II.

But the omission did not seem to surprise anyone. In his address to the assembly Tuesday, Rabin recalled the mixed relationship Israel has enjoyed with the world body, from its 1947 partition resolution endorsing the creation of the Jewish state, to the 1975 resolution equating Zionism with racism and its recision in 1991.

He also appeared to take pains to redress the General Assembly's omission by paying solemn tribute to Holocaust victims.

"I come here today in the name of the 6 million whose lives were turned into ashes, whose souls ascended to heaven in burning flames. We will never let them be forgotten," he said.

Rabin also thanked the international community for its support for the peace process and pledged to pursue it "until we have brought peace to the region. For our children and our children's children. That is our mission. We will fulfill it."

Rabin also urged the United Nations to resist complacency and fight terrorism, which he called "the world's cancer."

"Don't fool yourselves. Even if you ignore terror it can enter any of your homes. Terror must be defeated."

The prime minister also asked for help locating Israeli MIAs and POWs.

Rabin voiced the same concerns in a private meeting last Friday with U.N. Secretary General Boutros Boutros-Ghali.

Meanwhile, Jewish organizations active in international affairs used the U.N. anniversary as an opportunity to step up their work.

Officials of the American Jewish Committee, for instance, held 27 private diplomatic meetings in the three weeks since the opening of the General Assembly.

Although the number of dignitaries in one place at one time is unprecedented, the meetings reflect "our extensive ongoing relations with dozens of countries on every continent" rather than anything new, said David Harris, AJCommittee executive director.

The discussions focused on the AJCommittee's priorities, including the peace process, Israel's international diplomatic standing, anti-Semitism and human rights, Harris said.

The AJCommittee met in recent days, for instance, with the foreign ministers of Germany, France, Italy, China and other nations to discuss weapons development in Iran as well as Iran's support for international terrorism, he said.

The World Jewish Congress has held more than 24 meetings in recent weeks with international officials to advance Jewish interests, such as matters of restitution with Eastern European leaders.

The WJC also scheduled a meeting Tuesday night with Cuban leader Fidel Castro to discuss human rights.

The agency has been "working to strengthen the Jewish institutional presence in the nongovernmental community" at the United Nations, said Elan Steinberg, WJC executive director.

Harris Schoenberg, director of U.N. affairs for B'nai B'rith International, said the celebration was an ideal time to talk to diplomats about one of his most urgent concerns — reform of the Security Council, the U.N.'s strategic center and site of decisions about peacekeeping, sanctions and international security.

He has also joined others in pressing for Israel to have the opportunity to vie for a non-permanent seat on the council, which it is denied as a result of its exclusion for political reasons from any U.N. regional grouping.

Meanwhile, U.N. Watch, a nongovernmental organization with U.N. consultative status and affiliated with the World Jewish Congress, praised Libya's recent withdrawal of its candidacy for one of the 10 nonpermanent seats on the Security Council.