There have been calls for urgent talks to revive the nuclear agreement with Iran, despite Tehran attacking the French foreign minister's claim that it was building nuclear weapons as "absurd nonsense". Two days before Joe Biden is sworn in as US president, there are increasing signs that he will attempt to revive the Joint Comprehensive Plan of Action agreement that was meant to restrict Iran's nuclear ambitions. Despite heavy sanctions from President Donald Trump’s administration after the US left the deal in 2018, Iran has continued to enrich uranium as part of its efforts to make a nuclear bomb. Leading academics told <em>The National</em> that a deal should be negotiated to include restrictions on Iran's ballistic missiles and terrorism sponsorship in return for lifting sanctions and readmitting it into the international community. "They've got to act quickly because otherwise Iran is heading towards a nuclear weapon breakout and that's something that nobody can afford," said Dr Alan Mendoza, director of the Henry Jackson Society. “The Iranians have systematically breached every single one of JCPOA’s main provisions so the idea that we can simply return to the 2015 deal is ludicrous, because they are substantially further down the path to their nuclear endpoint.” His words came after Iran's Foreign Minister Mohammad Javad Zarif dismissed a claim by France's Jean-Yves Le Drian that Tehran was in the process of building up its nuclear weapons. "Avoid absurd nonsense about Iran," he tweeted, tagging Mr Le Drian. Germany, France and Britain have remained in JCPOA, an agreement that some commentators regard as no longer functioning. Mr Biden's European allies will hope his US administration acts before Iran's nuclear programme becomes unstoppable and also before the staging of elections in Iran this year that could bring in a more hard-line government. “The Iranians will try to exert a price for being brought back into negotiations that will mean getting rid of the Trump sanctions immediately,” said Prof Michael Clarke of the Royal United Services Institute. “I think the Iranians will be prepared to go back into the nuclear part of JCPOA, because they could live with that in terms of a 10-year moratorium on development, but they’ll have trouble agreeing to real restrictions on their ballistic missile development.” One trade-off for Iran will be greater recognition of its regional role by Europe, US and Middle East powers. Dr Mendoza, who condemned Iran for “systematically breaching” JCPOA, hoped Mr Biden’s plan would be a modified version of the 2015 deal with “more serious strictures on making sure that Iran actually has to roll back” its nuclear programme. “This deal also has to last in perpetuity, not merely for a period of time,” he said. “That type of deal will have a lot more support than the original plan. If it doesn’t, then we are going to see a very emboldened Iran and a lot of consternation with America’s allies in the Gulf and in Israel.” He called the negotiations a "high stakes” first major foreign policy test for the Biden administration. “Some in Iran will be saying, ‘here’s our chance to break out of this isolation and do something very different’, but there’s a strong hardline element who will be pushing the other way, saying, ‘well, Biden’s weak, let’s keep on doing what we’re doing because we’re going to win’.” Analysts believe there will be a narrow window of opportunity between Mr Biden taking office on Wednesday, January 20, and Iran's presidential election five months later. "The cleanest, easiest and simplest option is a mutual return to the JCPOA," Ilan Goldenberg of the Centre for a New American Security told <em>The Economist</em>. Prof Clarke said it was Europe's "dirty little secret" that JCPOA had been restricted to the nuclear proliferation issue. "The Iranians will want a more general deal because they want some legitimacy for their role as a regional power. So there may be a trade-off there which the US could explore." Reports from Israel suggest that Mr Biden’s administration has already begun low-level discussions with Iran on a return to the 2015 nuclear deal. Israel and the Gulf region will also want to see limitations on both Tehran’s ballistic missile programme and its support for terrorism as part of any wider deal. Iran has said it could welcome the return of the Americans to the agreement, but only after they lift sanctions. It has, however, rejected negotiation on other issues.