Netanyahu, who plans to send a deputy and two senior advisers to the April 12-13 conference instead, canceled his trip “after learning that some countries including Egypt and Turkey plan to say Israel must sign the NPT,” an Israeli official said.

By staying outside the 1970 Non-Proliferation Treaty (NPT), Israel has not had to forswear nuclear arms nor admit international inspectors to its Dimona reactor, which experts believe has produced plutonium for between 80 and 200 warheads.

Israel is viewed as the sixth country to have acquired nuclear weapons — a title it has never denied or confirmed.

Analysts at British defense specialists Jane’s believe the Jewish state has between 100 and 300 nuclear warheads, putting it among the more advanced nuclear weapons states and roughly on a par with Britain.

The London-based International Institute of Strategic Studies (IISS) estimates Israel has “up to 200” warheads deliverable on land-based short-range Jericho 1 and medium-range Jericho 2 missiles.

The Nuclear Threat Initiative, a US advocacy group co-created by Ted Turner, the founder of CNN and a former senator, puts the figure at 100 to 200.

Netanyahu’s attendance at the 47-country summit would have been unprecedented. Israeli premiers long shunned such forums, hoping to dampen foreign scrutiny on their nuclear secrets.

Aides said Netanyahu originally agreed to go after being reassured by the United States that the summit communiqué would focus on efforts to secure fissile materials and shun language challenging Israel’s nuclear “ambiguity” policy.

Such coordination between the allies has been clouded, however, by rifts over stalled Israeli-Palestinian peace talks.

A senior Egyptian diplomat said he had no knowledge of a plan to shift attention onto Israel at the summit and accused Netanyahu of trying to evade questions on the Palestinian issue. “We believe that Netanyahu withdrew from the summit because he did not want to face President Obama and is using Egypt and Turkey as an excuse,” he said.

But the Foreign Ministry in Ankara confirmed that Turkish Prime Minister Tayyip Erdogan, who has sharply escalated criticism of Israel since last year’s Gaza war, would demand at the summit that it disarm as part of a nuclear-free Middle East.

“Israel is the principal threat to peace in the region today,” French newspaper Le Monde quoted Erdogan as saying this week.

“Israel has nuclear weapons but doesn’t belong to the NPT. Does that mean that those who don’t sign the NPT are in a privileged position?”