US President Barack Obama has rejected a call by Israel for any nuclear agreement with Iran to be conditional on Tehran’s recognition of the Zionist entity, branding it a "fundamental misjudgment".

US President Barack Obama has rejected a call by Israel for any nuclear agreement with Iran to be conditional on Tehran's recognition of the Zionist entity, branding it a "fundamental misjudgment".

Obama told US radio network NPR Monday that demands for Iran to recognize the Zionist entity go beyond the scope of the agreement.

"The notion that we would condition Iran not getting nuclear weapons in a verifiable deal on Iran recognizing Israel, is really akin to saying that we won't sign a deal unless the nature of the Iranian regime completely transforms," he said in a drive to sell the deal to a hostile Congress.

"And that is, I think, a fundamental misjudgment."

Tel Aviv reacted angrily to the historic framework agreement on Iran's nuclear program announced last week, with a final accord due by June 30.

Prime Minister Benjamin Netanyahu demanded Sunday that Iranian recognition of Israel be written into the agreement.

Intelligence minister Yuval Steinitz told journalists Monday that while an earlier pledge by Obama to back Israel's security was appreciated, it did not outweigh the potential threat of a “nuclear-armed” Iran.

"If Iran will produce nuclear weapons, this is an existential threat to Israel," Steinitz said.

"Nobody can tell us that backing and assistance are enough to completely resist or to neutralize such a threat."