Director General of the International Atomic Energy Agency Yukio Amano said on Monday that any collapse of the 2015 nuclear deal, known as the Joint Comprehensive Plan of Action, would be a “great loss for nuclear verification and for multilateralism,” alluding to a US threat to pull out of it. US President Donald Trump has threatened to pull out of the deal unless Congress and European allies help "fix" it with a follow-up agreement. Amano, whose agency is monitoring Iranian compliance with curbs on its disputed nuclear activity imposed by the agreement, has long called the deal a "net gain" for nuclear verification, since it has provided the IAEA with more thorough oversight of Iran. Amano made the remarks in his introductory statement to the meeting of IAEA’s Board of Governors in Vienna Austria, on Monday March 5, 2018, IAEA website reported. In his speech, Amano evoked the possibility of the deal, officially known as the Joint Comprehensive Plan of Action (JCPOA), unraveling. "The JCPOA represents a significant gain for verification," Amano said, according to a text of his speech published by his agency. "If the JCPOA were to fail, it would be a great loss for nuclear verification and for multilateralism." Amano said Iran was implementing its commitments under the deal, which also lifted painful economic sanctions against the Islamic Republic. He confirmed the findings of a quarterly, confidential IAEA report on Iran issued last month. As mentioned in the report, the IAEA has requested clarification from Iran about its plans to develop nuclear marine propulsion, Amano said, suggesting the IAEA has still not heard back from the Islamic Republic. "The agency has requested Iran to provide further clarifications regarding its plans relevant to the development of the nuclear fuel cycle related to naval nuclear propulsion," Amano told the closed-door meeting of 35 member states. Iran has long said publicly that it plans to develop nuclear propulsion for naval vessels but analysts and diplomats say remains a distant prospect. It formally notified the IAEA of that intention in January in what was widely seen as a diplomatic warning shot aimed at the Trump administration, which reversed a policy of detente with Iran introduced by his predecessor Barack Obama. But the move prompted the IAEA to ask what exactly Irans plans are. Frances foreign minister visited Iran on Monday on a delicate mission to affirm European support for the nuclear deal that opened up Irans economy, while echoing US concern about Tehrans ballistic missile program and role in Middle East conflicts. Trump has repeatedly threatened to pull out of the deal. In his new policy declared on January 12, Trump gave Congress and European allies four months to fix what he claims “disastrous flaws” in the deal otherwise he will pull the US out of it.