Washington - President Donald Trump has kicked the fate of the landmark Iran nuclear deal to the US Congress, ignoring the advice of worried allies as he vowed to confront the "fanatical regime" in Tehran.Trump defended his decision to "decertify" Iran's compliance with the 2015 agreement in a speech Friday that evoked US grievances dating back to the 1979 Islamic Revolution.He railed against the "Iranian dictatorship, its sponsorship of terrorism, and its continuing aggression in the Middle East and all around the world."And he warned he could rip up the 2015 agreement curbing Iran's nuclear program "at any time," saying it had failed to address Iranian subversion in its region and its illegal missile program.Sharp reactionsReaction to the US move came fast and furious, with Iranian President Hassan Rouhani declaring the United States was "more than ever against the Iranian people."Former US secretary of state John Kerry, who negotiated the nuclear deal, accused Trump of "creating an international crisis" and called on the US Congress to stand in the president's way."It endangers America's national security interests and those of our closest allies," Kerry said.In a cautious but unmistakable rebuke, the leaders of Britain, France and Germany said the deal remained in "our shared national security interest.""We encourage the US administration and Congress to consider the implications to the security of the US and its allies before taking any steps that might undermine" the deal.French President Emmanuel Macron later said he was considering visiting Iran after speaking by phone with his Iranian counterpart.The International Campaign to Abolish Nuclear Weapons, which was awarded this year's Nobel Peace Prize, also denounced the move, saying it makes proliferation more likely.Hand-off to CongressTrump stopped short of scrapping the deal outright, however, leaving Congress and US allies some room for maneuver.The Republican-controlled Congress now has 60 days to decide whether to reimpose sanctions on Iran - a step that if taken would almost certainly doom the accord.The US president said he supports efforts in Congress to work on new measures to address the broader threats posed by Iran without immediately torpedoing the nuclear deal."However, in the event we are not able to reach a solution working with Congress and our allies, then the agreement will be terminated," Trump said, in a televised address from the Diplomatic Room of the White House.Proposals by Republican Senators Tom Cotton and Bob Corker to introduce "trigger points" for new sanctions and extend sanctions beyond a pre-agreed deadline have spooked allies, who believe it could breach the accord.But it remains unclear if their proposals can garner the 60 votes needed to pass the Senate.Trump also backed away from designating Iran's powerful Revolutionary Guards Corps as a terror group, a move that would have triggered sanctions and almost certain Iranian retribution.Apart from running swaths of Iran's economy and its ballistic missile program, the Revolutionary Guards are accused of guiding proxy forces across the region, from Hezbollah in Lebanon, to the Huthis in Yemen and Shiite militias in Iraq and Syria."We have considered that there are particular risks and complexities to designating an entire army, so to speak, of a country," Secretary of State Rex Tillerson said.Instead, the US Treasury said it had taken action against the Islamic Revolutionary Guards under a 2001 executive order to hit sources of terror funding and added four companies that allegedly support the group to its sanctions list.'The worst deal'Trump has repeatedly pledged to overturn one of his predecessor Barack Obama's crowning foreign policy achievements, deriding it as "the worst deal" and one agreed to out of "weakness."The agreement stalled Iran's nuclear program and marginally thawed relations between Iran and what Tehran dubs the "Great Satan," but opponents, and even some supporters, say it also prevented efforts to challenge Iranian influence across the Middle East.Since coming to office, Trump has faced intense lobbying from international allies and much of his own national security team, who argue the nuclear deal should remain in place.Both the US government and UN nuclear inspectors say Iran is meeting the technical requirements of its side of the bargain, dramatically curtailing its nuclear program in exchange for sanctions relief.Trump claimed support for his move in a tweet late Friday, while suggesting that his critics among US allies were placing trade profits ahead of security."Many people talking, with much agreement, on my Iran speech today. Participants in the deal are making lots of money on trade with Iran!" he wrote on Twitter.