Arab states in the United Nations nuclear assembly on Friday won narrow approval of a resolution urging Israel to put all its atomic sites under the world body's inspection and join the Non-Proliferation Treaty.
Israel deplored the measure for singling it out while many of its neighbors remained hostile to its existence, and said it would not cooperate with it.
The non-binding resolution, which passed for the first time in 18 years of attempts thanks to more developing nation votes, voiced concern about "Israeli nuclear capabilities" and urged the International Atomic Energy Agency to tackle the issue.
Israel is one of only three countries worldwide along with India and Pakistan outside the nuclear NPT and is widely assumed to have the Middle East's only nuclear arsenal, though it has never confirmed or denied this.
Iranian Ambassador Ali Asghar Soltanieh, whose country's disputed nuclear program is under IAEA investigation, told reporters Friday's vote was a "glorious moment" and "a triumph for the oppressed nation of Palestine".
UN Security Council members Russia and China also backed the resolution, which passed by 49 votes to 45 against in a floor vote at the IAEA's annual member states conference.
The vote split along Western and developing nation lines. There were 16 abstentions.
"Israel will not cooperate in any matter with this resolution which is only aiming at reinforcing political hostilities and lines of division in the Middle East region," chief Israeli delegate David Danieli told the chamber.
Western states said it was unfair and counterproductive to isolate one member state. They said an IAEA resolution passed on Thursday, urging all Middle East nations to foreswear atomic bombs, included Israel and made Friday's proposal unnecessary.
Arab nations said Israel had brought the resolution on itself by having never signed the 40-year-old NPT.
Before the vote, U.S. Ambassador Glyn Davies said the resolution was "redundant ... Such an approach is highly politicized and does not address the complexities at play regarding crucial nuclear-related issues in the Middle East."
Calling the resolution "unbalanced", Canada tried to block a vote on the floor with a "no-action motion". But the procedural maneuver lost by an eight-vote margin. The same motion prevailed in 2007 and 2008.
A senior diplomat from the non-aligned movement of developing nations said times had changed.
"People and countries are bolder now, willing to call a spade a spade. You cannot hide or ignore the truth, the double standards, of Israel's nuclear capability forever," he said.
"The new U.S. [Obama] administration has certainly helped this thinking with its commitment to universal nuclear disarmament and nuclear weapons-free zones," they said.
The measure was last voted on in 1991 when it passed by 39-31 with 13 abstentions when IAEA membership was much smaller.
Since then there have only been official summaries of debate on this item or successful motions for adjournment or no action.