Israel's prime minister was given "unequivocal assurances" from US President Barack Obama that a UN accord agreeing to talks on a nuclear weapons-free Mideast would not endanger the Jewish state, a senior Israeli official said Sunday.

"Two weeks ago, Prime Minister Benjamin Netanyahu received unequivocal assurances that included significant upgrade of Israel's strategic and deterrent capabilities in a personal message conveyed by President Obama," the official said in a statement in Toronto, where Netanyahu was on a visit.

The premier was "promised that there would be no resolutions adopted at the UN that would hurt the vital interests of Israel," the official added, referring to Friday's landmark agreement reached by the members of the nuclear Non-Proliferation Treaty (NPT) that singles out Israel and seeks a 2012 conference on establishing a Middle East zone free of nuclear weapons.

The document calls on Israel to join the NPT and urges it to open its facilities to inspection, but makes no mention of Iran's controversial nuclear program.

Israel has already said it would refuse to participate in the 2012 conference and slammed the resolution as "deeply flawed and hypocritical."

In an apparent reference to the call, Netanyahu told some 7,000 members of Toronto's Jewish community at a pro-Israel rally on Sunday that Israel would never agree to these demands.

"The establishment of the state of Israel has given the Jewish people the power to repel the attacks on the Jewish people," Netanyahu said.

"There are those who want to strip Israel of that power. I promise you that will never happen, Israel will never ever give up the power to defend itself."

Netanyahu later travelled to Ottawa where he was to hold a series of meetings with Canadian Prime Minister Stephen Harper, one of Israel's strongest supporters in the international community.

Sunday's statement was seen as an Israeli government effort to downplay the surprise, worry and outrage back home over the NPT agreement ahead of Netanyahu-Obama talks scheduled for Tuesday at the White House.

It appeared to be tamping down any anger Israel may have with the United States for supporting the agreement despite intensive Israeli efforts to block it.

Consternation over the resolution has welled up in Israel, where the top-selling Yediot Aharonot daily said Netanyahu's government was "furious with the Obama administration for having failed to prevent the resolution from passing... and for choosing to support it."

"The American support for the resolution, after decades in which it supported Israel on this issue, came as a complete surprise," the paper said, noting that Israel, in talks between Netanyahu and Obama aides, had been promised that the resolution would not focus on Israel.

In Sunday's statement, the Israeli official stressed that "Netanyahu acted in the last two months to ensure that the resolution at the UN would have no practical effect on Israel.

"These efforts included continuous contact between Prime Minister Netanyahu and President Obama."

Officials with Netanyahu have said the two leaders will discuss the accord when they meet in Washington, their first face-to-face talks since a frosty White House meeting in March which was viewed by many as an attempt to humiliate Netanyahu in the wake of a spat over settlements.

Israel is widely believed to be the only nuclear power in the Middle East, with around 200 warheads, but has maintained a policy of deliberate ambiguity about its capabilities since the mid-1960s.