The future of the historic nuclear agreement with Iran is in the air with the prospect that a Donald Trump administration could take steps that would cause Iran to abandon its commitments, experts said Wednesday.

Some characterized Trump’s election as a death knell for the deal, which was reached in 2014 and put into effect in January. It imposes limits on Iran’s nuclear program and its ability to build atomic weapons for at least 10 years in exchange for lifting most international sanctions.

“I think it’s basically the end game for the deal,” said Richard Nephew, a Columbia University fellow who was the lead sanctions expert on the U.S. negotiating team.

“It’s very hard for me to see, based on the rhetoric, letting it stand as is, or not doing something that forces the Iranians to walk away.”

Which “red lines” drawn during negotiations ended up in the deal

Though it has been applauded by allies that negotiated alongside the United States — Britain, France, Germany, China, Russia and the European Union — the agreement has been heavily criticized in Congress. Republican lawmakers in particular say it has rewarded Iran for taking U.S. citizens prisoner and enabled the country’s aggression in regional conflicts in Syria and Yemen.

“My number one priority is to dismantle the disastrous deal with Iran,” Trump said in a speech to the pro-Israel lobbying group AIPAC during the campaign. He later said he would try to renegotiate the agreement and increase U.S. sanctions against Iran.

Iran is concerned enough about what Trump may do that senior officials on Wednesday urged a Trump administration to live up to commitments made by the United States.

President Hassan Rouhani, a relative pragmatist who pushed for the deal hoping to open Iranian’s reclusive society to the international economy, said Trump cannot change the agreement.

“Iran’s understanding of the nuclear deal was that the accord was not concluded with one country or government but was approved by a resolution of the U.N. Security Council, and there is no possibility that it can be changed by a single government,” he said on Iran state television Wednesday.

Foreign Minister Mohammad Javad Zarif, who negotiated the agreement on behalf of Iran, said the United States must stick to the agreed-upon details.

An Iranian woman walks past a mural on the wall of the former U.S. embassy in Tehran. (Atta Kenare/AFP via Getty Images)

“Every U.S. president has to understand the realities of today’s world,” he said Wednesday, as reported by the Tehran Times. “The most important thing is that the future U.S. president sticks to agreements, to engagements undertaken.”

Uncertainty in Tehran is not necessarily a bad thing, said Mark Dubowitz, head of the Foundation for Defense of Democracies who has testified frequently in Congress opposing the deal.

“I could see a Trump administration beginning to threaten the use of American power, and put the Iranians to a choice between severe sanctions and potential military action, or going back to renegotiate some key elements of the deal,” he said, citing sunset provisions that gradually begin to lift some limitations after seven to 15 years.

Dubowitz added: “There’s always the risk the United States ends up isolated, as the Europeans, Chinese and Russians scramble to cut side deals with the Iranians. But one should never underestimate the power of U.S. secondary sanctions and the fear that creates in the marketplace — a fear that has now been intensified as a result of a President Trump.”

Trump’s statements have at times been contradictory, adding a further element of confusion into the predictions. But he will probably not act solely on his own instincts.

“He will be able to call upon a considerable body of effort on the part if all those mobilized trying to block the deal last year, aimed at looking for ways to undermine its provisions, to toughen the measures put in place and to force our negotiating partners to go along with a much harsher stance,” said Suzanne Maloney, deputy director of the foreign policy program at the Brookings Institution.

“To my mind, that’s highly unrealistic,” she added. “This isn’t the sole issue a Trump administration is going to be at odds with our primary diplomatic partners over. It will already be a fraught relationship.”

The path forward should become clearer once Trump names his foreign policy team.

“To what extent will the Never Trump faction, which was wide in the policy community, begin to walk back on its absolutism in refusing to serve in his administration?” Maloney said. “I suspect some will.”