President Donald Trump and Iran's top diplomat traded sharp warnings on Tuesday, with Trump threatening 'bigger problems' than ever if Tehran restarts its nuclear program. Foreign Minister Mohammad Javad Zarif put the president on notice, telling The Associated Press if the U.S. pulls out of the nuclear deal, Iran 'mostly likely' would abandon it, too. In a wide-ranging interview, Zarif said a U.S. withdrawal from the landmark 2015 accord would undermine Trump's talks with North Korea by proving that America reneges on its promises. He said if Trump re-imposes sanctions, 'basically killing the deal,' Iran would no longer be bound by the pact's international obligations, freeing it up to resume enrichment far beyond the deal's strict limits. 'If the United States were to withdraw from the nuclear deal, the immediate consequence in all likelihood would be that Iran would reciprocate and withdraw,' Zarif said. He added: 'There won't be any deal for Iran to stay in.' As Zarif spoke in New York on Tuesday, Trump was meeting at the White House with French President Emmanuel Macron, who has been leading an effort by France, Britain and Germany to find 'fixes' to the deal that would satisfy Trump's objections. Few expect such a solution can be found by May 12, the date on which Trump has said he'll leave the deal if there's no fix agreed to with the Europeans. 'No one knows what I'm going to do on the 12th, although Mr. President, you have a pretty good idea,' Trump said, referring to Macron. He said if he does withdraw, he would look to see 'if it will be possible to do a new deal with solid foundations, because this is a deal with decayed foundations.' In a bleak warning to Tehran, Trump added that if Iran ever threatens the United States, 'they will pay a price like few countries have ever paid.' Iran has been working feverishly to frame Trump's expected withdrawal as a major blot on the United States, just as America's closest allies in Europe try to persuade the president not to rip it up. U.S. and European officials say they've made major progress on two of Trump's demands — on nuclear inspections and Iran's ballistic missiles program. But talks have stalemated on Trump's third demand: that the deal be extended in perpetuity, rather than letting restrictions on Tehran to 'sunset' after several years. Iran has outright rejected any changes to the deal, arguing that it's unfair to impose more demands beyond what Tehran agreed to already. Trump's strategy relies on the assumption that if the U.S. and the Europeans unilaterally agree to new demands, Iran will back down and voluntarily comply in order to continue enjoying the benefits. Under the 2015 deal brokered by President Barack Obama and world powers, Iran agreed to nuclear restrictions in exchange for billions in sanctions relief. And even if a so-called add-on deal with the Europeans is achieved, there is no guarantee it will satisfy Trump. His closest aides have said they can't predict with certainty what conditions would be enough to keep him in the pact. As Trump prepares for a high-stakes summit with North Korean leader Kim Jong Un aimed at resolving nuclear weapons concerns, Zarif emphasized that U.S. credibility was at stake. He said Iran would welcome lower tensions on the Korean Peninsula, but that Trump was showing the world that the U.S. is 'not a trustworthy, reliable negotiating partner.' 'They're prepared to take everything that you've given, then renege on the promises that they have made in the deal,' Zarif said. 'That makes the United States a rather unlikely partner in any international agreement. And unfortunately this track record is not just limited to the nuclear deal. It includes the Paris climate agreement, the Trans-Pacific Partnership, and a lot of other freely undertaken commitments of the United States.' Iran has long insisted its nuclear program was peaceful and not oriented toward building weapons. Yet in the interview, Zarif suggested that those concerned that Tehran was racing toward a bomb would have much more to fear if it were no longer bound by limits on its enrichment and processing. 'It would be a completely different situation, from the perspective of those who made a lot of noise about Iran's nuclear program to begin with,' he said. He also pointed out that if Trump upends the nuclear deal, Iran could also choose to leave the global Nuclear Non-Proliferation Treaty, which aims to stop the spread of nuclear weapons. Iran signed that treaty decades ago, and though Zarif said Iran's government isn't advocating an exit, it is 'one of the options that is being advocated by some' in Iran. Zarif spoke to the AP at the official residence of Iran's ambassador to the U.N., alongside Central Park. The top Iranian diplomat is in the United States this week on a long-shot bid to try to salvage the deal, while laying the groundwork for the United States to bear the blame on the global stage if Trump ultimately pulls out. Addressing the conflict in Yemen, he said Iran is urging 'everybody' to stop attacking civilian areas — including the Houthis. The Iran-backed Shiite rebels control much of Yemen and have been lobbing missiles at Saudi Arabia, which is leading a coalition fighting the Houthis with support from the U.S. The Trump administration and others insist that Iran is illicitly funneling missiles and other weapons to the Houthis, a charge that Tehran has repeatedly denied. 'All over, no matter where you go in the Middle East, you see the fingerprints of Iran behind problems,' Trump said. His ambassador to the United Nations, Nikki Haley, has paraded missile parts ostensibly recovered in Saudi Arabia in front of reporters and U.N. Security Council diplomats, arguing that they bear markings and other characteristics proving their Iranian origin. But Zarif laughed off her claims. 'I'm not saying Ambassador Haley is fabricating, but somebody is fabricating the evidence she is showing,' Zarif said. As Trump pushes to withdraw U.S. troops from Syria, Zarif gave no signs that Iran plans to do the same. The Iranian military advisers and Iran-backed Shiite militias aiding Syrian President Bashar Assad are a profound concern for the United States and its closest Mideast ally, Israel. 'We are there as long as that objective needs our presence, and as long as the Syrian government asks us to be there,' Zarif said.