The US made clear on Monday that sanctions on Iran would have to be phased out gradually under a nuclear pact and President Barack Obama poured cold water on an Israeli demand that a deal be predicated on Tehran recognizing Israel.

“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,” Obama said in an interview with National Public Radio (NPR).

“That is, I think, a fundamental misjudgment... We want Iran not to have nuclear weapons precisely because we can't bank on the nature of the regime changing,” he said.

He added that Iran should stop threatening Israel and cease engaging in proxy wars around the Middle East, but has tried to separate concerns about Iran’s regional role from the tentative deal finalized Thursday.

“If suddenly Iran transformed itself to Germany or Sweden or France, then there would be a different set of conversations about their nuclear infrastructure,” he added.

Meanwhile White House spokesman Josh Earnest said there was no ambiguity about the US demand that sanctions on Tehran be lifted in phases under a final deal, but details still had to be negotiated.

“It has never been our position that all of the sanctions against Iran should be removed from Day One,” he told a briefing.

The White House is working aggressively to convince US lawmakers and other critics to embrace the framework agreement reached on Thursday between Iran, the United States and five other major powers.

The framework was a major step toward a final deal but did not include an agreement on the timing and scope of sanctions relief. Many other issues also must be hammered out before the end-of-June deadline for a final accord.

Iran's negotiators have interpreted the outline differently, saying sanctions would be lifted immediately once an accord is signed.

Earnest said Washington would want to see sustained compliance by Iran first and Iran would be more likely to comply if it knew sanctions could be applied again.

A key US ally, Saudi Arabia, sounded a note of caution on the agreement.

Adel al-Jubeir, the Saudi Ambassador to Washington, told reporters the oil-rich Kingdom wants to see more details on the restrictions on Iran's nuclear work, nuclear inspections, and when international sanctions on Tehran would be lifted.