Facing deep skepticism on multiple fronts, President Barack Obama ramped up lobbying Monday for a framework nuclear deal with Iran, one of the toughest sells of his presidency.

Yet critics from Jerusalem to Washington warned they won’t sit idly by while Obama and world leaders pursue a final accord that would leave much of Iran’s nuclear infrastructure intact.

The White House deployed Energy Secretary Ernest Moniz — a nuclear physicist — to offer a scientific defense of a deal, which he said would block all Iranian pathways to a nuclear weapon. He described the emerging deal as a “forever agreement,” disputing skeptics who contend it would merely delay Iran’s progress toward a bomb.

“This is not built upon trust,” Moniz said, describing a set of intrusive inspections that would tip off the global community if Iran attempts to cheat. “This is built upon hardnosed requirements in terms of limitations on what they do, at various timescales, and on the access and transparency.”

Under the agreement, Moniz said, Iran would agree — in perpetuity — to a beefed-up level of inspection by the International Atomic Energy Agency. Other elements of the inspection regimen, such as those dealing with storage and mining of nuclear materials, would end sooner.

Moniz acknowledged that over time, however, some restrictions on Iran’s nuclear activities might be eased if the world gains confidence that its program is being operated for purely peaceful purposes.

Skeptics were undeterred.

Senate Majority Leader Mitch McConnell, R-Ky., just back from the Middle East, questioned why Iran would be allowed to retain more than 6,000 centrifuges for processing nuclear fuel, despite Obama’s earlier suggestion that he was pursuing a deal that would end Iran’s nuclear program, not simply shrink it.

“The parameters of the interim deal, in essence, establish an internationally recognized, 10-year nuclear research and development program,” McConnell said.

The strongest international criticism came from Israel, where leaders consider a nuclear-armed Iran to be an existential threat. Israel’s minister for strategic affairs, Yuval Steinitz, said Israeli military action against Iran’s nuclear program remains an option, and Prime Minister Benjamin Netanyahu has also insisted any final deal must include a “clear and unambiguous Iranian recognition of Israel’s right to exist.”

Obama, in an NPR News interview Monday, said requiring formal recognition of Israel was a “fundamental misjudgment,” tantamount to insisting that the Iranian regime completely transform as a prerequisite to a deal.

“We want Iran not to have nuclear weapons precisely because we can’t bank on the nature of the regime changing,” Obama said.

In Washington, members of Congress from both parties have raised concerns about the pace at which U.S. and international sanctions on Iran would be lifted in exchange for rolling back its nuclear program.

White House spokesman Josh Earnest said Iran continues to press publicly for a deal that would lift all sanctions immediately. The U.S. and its negotiating partners — Russia, China, France, the U.K. and Germany — have been pushing for phased-in sanctions relief. But the fact that such a key matter was left unsettled in the framework deal has fueled further doubts about the negotiations, which are supposed to be concluded by June 30.

Lawmakers are pushing to give Congress a say in whether the agreement should stand. Senate Foreign Relations Chairman Bob Corker, R-Tenn., backs legislation that would not only let lawmakers vote to approve or reject the bill, but would also prevent Obama from using his own authority to temporarily waive existing U.S. sanctions while Congress debates the deal.

The Foreign Relations panel plans to vote on the measure next week. With support assured from nearly all Republicans, the bill would need only a handful of defecting Democrats to support the bill to override a promised veto from Obama.

A number of Democrats have indicated concerns, raising the prospect of the first veto override of Obama’s presidency.

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Obama, in a weekend interview, suggested he might be open to another way for Congress to register its views on the deal without encroaching on his prerogative to conduct foreign policy. That led to speculation that Obama might support proposals for Congress to take a nonbinding resolution. But Earnest said the White House opposes any and all votes by Congress — other than an eventual vote to fully lift the sanctions Congress has slapped on Iran.

The Obama administration has sought to persuade lawmakers, foreign leaders and advocacy groups to embrace or at least stomach the deal. More than a dozen top officials fanned out to brief concerned parties, including Obama’s chief of staff, national security adviser, U.N. ambassador and secretaries of State and Treasury.

Those officials were echoed by outside voices, such as the Arab American Institute and the left-leaning Israel advocacy group J Street, that joined Monday to lend their support to the deal. And a group of more than 50 foreign policy veterans, including former Secretary of State Madeleine Albright and former Sen. Richard Lugar, R-Ind., published an open letter approving of the deal.