The UN atomic watchdog rejected Friday an Arab-backed resolution against Israel which the United States and its Western allies feared could have jeopardised newly relaunched Middle East peace talks.

The International Atomic Energy Agency (IAEA), on the last day of its annual general conference, voted against a non-binding resolution urging Israel to accede to the nuclear Non-Proliferation Treaty (NPT).

The paper -- which Washington had asked Arab countries not to table at all for fear it could jeopardise a conference on a nuclear weapons-free Middle East to be held in 2012 -- was rejected by the 151-member general assembly with 51 votes against it, 46 votes in favour and 23 abstentions.

In the run-up to this week's conference, Washington had even flown in US President Barack Obama's top nuclear advisor, Gary Samore, to try to persuade Arab nations to drop their plans, warning that it could also sour newly restarted peace talks between Israel and the Palestinians.

Israeli ambassador Ehud Azoulay -- who prior to the vote had warned that adopting the resolution would deal a "fatal blow" to efforts towards "better regional security in the Middle East" -- welcomed the outcome.

The Jewish state "hopes that the positive spirit manifested by the conference will prevail in the years to come. Israel pledges to do its utmost to promote such spirit and dialogue," he said.

Back in 2009 the resolution, which is purely symbolic, had been adopted by a very narrow majority of 49 in favour and 45 against.

A number of states that voted in favour last year chose to abstain this year. One of them was Singapore, which argued that the resolution would not have been "helpful at this delicate moment of history."

It was a contentious paper which would unlikely have helped "the ongoing Middle East peace talks or encourage all countries in the Middle East to participate in the 2012 conference," the Singapore delegate said.

Another abstention was Thailand, which was "encouraged" by the resumption of the direct peace talks between Israel and the Palestinians.

"Thailand welcomes these positive developments and would like to see the conducive atmosphere ... maintained to facilitate the convening of a conference in 2012 with the participation of all states in the Middle East," its delegate said.

US ambassador Glyn Davies acknowledged that the Arab states would probably view the vote as a defeat.

"I know that the atmosphere here in Vienna always takes a big hit when you have a very divisive and a close vote like this," he told reporters.

But once tempers had cooled, he hoped the Arab states would see the outcome as a "beginning, not an end," Davies said, adding that there were "no winners nor losers".

The vote "sends the right, positive signal to the peace process and really allows that process to go ahead," he said.

Iranian ambassador Ali Asghar Soltanieh, on the other hand, accused Israel and its allies of pursuing a policy of "double standards".

"What the US and others did today in fact undermined" the NPT, he said.

The vote was a "setback for the NPT. It damages the integrity of the NPT," Soltanieh said.

Israel and its allies "polarised the member states. Rather than defusing tension, they created tension, they created confrontation."

And Soltanieh vowed that the Arab states were all the more determined to table the same resolution again next year and redouble their efforts to win over supporters.

Earlier this week, Israel's nuclear chief Shaul Chorev reiterated the Jewish state's stance that acceding to the NPT would run against its national interests.