NEW YORK — Israel and its supporters are applauding a breakthrough for the country at the United Nations, a body that many believe has long treated the Jewish state unfairly.

Israel — the only U.N. member country that has been excluded from a regional group — was formally invited last Friday to join the Western European and Others Group (WEOG).

Tuesday, in a letter from U.N. Ambassador Yehuda Lancry, Israel accepted the invitation.

Later in the day, Lancry told Jewish organizational leaders that this marked a "historic turning point for Israel."

A statement issued by Israel's Foreign Ministry said the WEOG admission "marked the end of four decades of discrimination and injustice."

The temporary membership will give Israel a stronger voice in U.N. affairs.

But while heralding the move, pro-Israeli voices say they are still concerned about some of the membership "modalities," or conditions, imposed on its acceptance.

The main issues of concern: Israel can participate only in WEOG activities based at the U.N.'s New York headquarters and Israeli representatives will be barred for two years from running for positions on U.N. councils.

Israel will be excluded from WEOG discussions and consultations in Geneva, Nairobi, Rome and Vienna, effectively barring it from U.N. talks on human rights, racism and a number of other issues.

Israel's membership in the 26-member U.N. group, which includes the United States and Canada, is conditional in that it continue to apply for the more geographically appropriate Asia group.

That group, which includes Israel's most intransigent foes Iran and Iraq, has consistently rejected Israel's applications.

Israel must renew its WEOG membership every four years.

For decades, Israel has been the only U.N. member shut out of a regional group.

"We're ecstatic. Our foot is in the door," said Jeff Helmreich, press officer for Israel's U.N. mission. "But our happiness is tempered by the fact that we will have to accept certain conditions that distinguish us from other full members."

David Harris, the executive director of the American Jewish Committee, said Israel's admission marks "the start of a new era" but that the next goal is to "expand Israel's membership."

Harris Schoenberg, chair of the U.N. caucus of Jewish non-governmental organizations and a representative of B'nai B'rith International, described the invitation as "a huge step forward but clearly incomplete."

Both the AJCommittee and B'nai B'rith say modifying the modalities will be a priority in the future.

Nonetheless, they and the Israeli mission say they are celebrating the new status and that it will allow Israel to argue its positions from the inside, rather than the outside.

Israel was inching toward WEOG membership in the mid-1990s until the 1995 assassination of Prime Minister Yitzhak Rabin.

The Europeans were loathe to reward Benjamin Netanyahu with WEOG membership because of his perceived intransigence in peace negotiations with the Palestinians.

The European outlook changed with last year's elections of Prime Minister Ehud Barak.

The advocacy of Richard Holbrooke, U.S. ambassador to the United Nations, has also been credited with pushing Israel's position.