President Trump, who has called the Iran nuclear agreement the “worst deal ever,” has found a way to distance himself from it symbolically without causing an immediate rupture with Iran or U.S. allies who want to keep the accord in place.

Trump announced Friday his refusal to re-certify Iran's compliance with the 2015 agreement, which prevents Iran from trying to develop nuclear weapons for at least a decade in exchange for relief from international economic sanctions.

But Trump will not ask Congress to re-impose sanctions right away, a move that could prompt Iran to back out of the deal and resume its nuclear development program —much to the dismay of other world powers who signed onto the deal along with the U.S.

Congress requires the president to certify Iran's compliance with the agreement every three months. Despite Trump's refusal to do so this time, there are many reasons why Congress may be unwilling to take punitive action against Iran on its own.

For one thing, U.N. inspectors say Iran is in compliance, and there may be little appetite for a new crisis involving nuclear weapons on top of the mounting tensions with North Korea' over its nuclear program.

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In addition, the deal has strong support among businesses eager to sign deals with oil-rich Iran. Boeing has a $3 billion contract to provide commercial aircraft.

Members of Trump’s own administration, including Defense Secretary Jim Mattis, have lobbied against undermining the agreement, which was also signed by China, France, Germany, Russia and the United Kingdom. “If we can confirm that Iran is living by the agreement, if we can determine that this is in our best interest, then clearly we should stay with it," Mattis recently told Congress.

Trump, Israel and other critics of the deal, signed by President Obama, question whether Iran can cheat and secretly develop nuclear weapons without detection, an argument disputed by U.N. inspectors.

These critics also complain that the lifting of sanctions gives Iran billions of dollars in new funds to sponsor terrorist organizations around the world and develop ballistic missiles, which are not covered under the accord.

While many in Congress share that view, so long as they refrain from imposing new sanctions, the agreement would stay in place, said Michael Rubin, an analyst at the American Enterprise Institute. “Decertification isn’t synonymous with walking away from the deal,” he said.

If Congress imposed sanctions, prompting Iran to renege on the deal, "that’s a twofer” for the Iranians, Rubin said: Iran has already obtained benefits from the lifting of sanctions and now could restart its nuclear program as well — and blame it all on the United States.

New sanctions would endanger billions of dollars in potential investments that have already been negotiated. It would also anger U.S. allies, including France, which has urged the U.S. not to discard the nuclear deal. “Proponents of the agreement are saying American credibility is at stake, especially with European allies,” Rubin said.

Rather than push to scuttle the agreement, Trump plans to call for new negotiations to modify it. Fellow critics have urged the U.S. and its allies to force Iran to accept modifications, such as tighter restrictions on missile tests and funding radical militias in the Middle East.

That approach is a long shot. The Iranian government has repeatedly ruled out renegotiating any part of the agreement. “It will be a great pity if this agreement were to be destroyed by rogue newcomers to the world of politics,” Iranian President Hassan Rouhani said.

Even Trump is "not particularly optimistic" that the agreement can be fixed, Secretary of State Rex Tillerson said. "We may not be able to fix the deal."

Trump said Friday that if Iran refuses to modify the agreement, he'll formally terminate it and order sanctions slapped back on Iran.

It’s possible that the White House could work with Congress to threaten severe sanctions as a way to get Iran to agree to renegotiate, said Luke Coffey, an analyst at the Heritage Foundation. But he also acknowledged that is unlikely.

“I don’t see why Iran would want to renegotiate anything since the deal is so favorably on their side,” he said.