WASHINGTON -- Addressing an influential pro-Israel lobbying group in March, Donald Trump said that the landmark nuclear deal signed with Iran was a disaster and that dismantling it would be his "No. 1 priority."
Now, a day after Trump pulled off a stunning victory to capture the U.S. presidency, observers are watching closely for signs that his administration could indeed follow through on this threat when he takes office in January.
That possibility, and the concerns it has triggered, was quickly underscored in Tehran just hours after Trump's victory was announced early on November 9, with Iranian leaders calling on the U.S. president-elect to ensure that the deal, known as the JCPOA, was not undone.
"Iran's understanding in the nuclear deal was that the accord was not concluded with one country or government but was approved by a resolution of the UN Security Council," Iranian President Hassan Rohani said on state television. "There is no possibility that it can be changed by a single government."
The deal, signed in July 2015 and brokered by Washington, Moscow, and several Western states, curtailed Iran's growing nuclear ambitions in exchange for lifting sanctions that had crippled Iran's economy.
President Barack Obama's administration, which engaged in years of back-channel diplomacy to bring the deal to fruition, hailed it an unqualified success and a high point of his foreign-policy agenda.
Many Republicans had grave doubts, saying the deal only delayed Iran's ability to enrich enough uranium to build a nuclear weapon. Those doubts were amplified by the strident rhetoric of Israeli Prime Minister Benjamin Netanyahu, who argued before Congress that the deal "would all but guarantee Iran gets nuclear weapons."
WATCH: Iranians Discuss Trump Victory
One suggestion that Netanyahu's policies toward Iran might get a warmer reception in a Trump administration was the Israeli leader's announcement on November 9 that he had spoken to Trump by telephone, and that Trump had invited him to visit Washington "at the first opportunity."
United Nations inspectors said in May that Iran was keeping its stocks of uranium and heavy water within the deal's limits, something they reaffirmed on November 9 in their latest quarterly reports.
Still, those assurances did little to allay the agreement's critics, and it became an issue on the campaign trail for Trump and other Republican candidates.
Trump later said he would have negotiated a better deal, with more restrictions, but he also suggested that it would be hard to completely rip up the agreement, which was backed by a UN resolution.
Tom Collina, policy director at the Ploughshares Fund, a Washington research organization that has backed the agreement, says that could signal that despite Trump's campaign rhetoric, it seems unlikely he will jettison the deal.
"It really does seem like it's this deal or nothing, and I'll reemphasize: This deal is working. Facts are the facts, which is that the deal has capped and reversed and scaled back Iran's nuclear program in a very important way," Collina tells RFE/RL.
"What would he replace it with it and how it would benefit U.S. security? It's not at all clear to me," he adds.
Agreeing With Khamenei?
Iranian Foreign Minister Mohammad Javad Zarif, who was Tehran's lead negotiator for the JCPOA, echoed Rohani's statement that Trump must remain committed to the deal.
"Every U.S. president has to understand the realities of today's world," Zarif was quoted as saying by the Tasnim news agency.
"The most important thing is that the future U.S. president stick to agreements, to engagements undertaken," he said.
In Washington, White House spokesman Josh Earnest told reporters on November 9 that the outgoing administration remained committed to the nuclear deal.
"This administration will be committed to implementing those policies through January 20, and we will live up to the commitments that we have made in each of those areas as we do so," he told reporters.
Susan Maloney, a foreign-policy scholar at the Washington-based Brooking Institution, argued that Trump's victory was a benefit to Iran's supreme leader, Ayatollah Ali Khamenei, who has been publicly critical of the deal.
"He will have the most cartoonish American enemy, he will exult in the…crash of the American economy, and he will be able to walk away from Iran's obligations under the JCPOA while pinning the responsibility on Washington," she told Reuters.
With reporting by Reuters