US President Donald Trump has condemned Iran as a "fanatical regime" and refused to continue certifying an international nuclear deal.
Trump said on Friday he was referring the deal to Congress and would consult allies on how to alter it, BBC reported.
He accused Iran of sponsoring terrorism and said he would deny the regime "all paths to a nuclear weapon".
International observers say Iran has been in full compliance with the 2015 deal freezing its nuclear programme.
But Trump said the deal was too lenient, and Iran had "committed multiple violations of the agreement":
On two occasions, he said, they had exceeded the limit of 130 tonnes of heavy water (a source of plutonium suitable for a nuclear bomb)
Until recently, the regime had failed to meet expectations in its operation of advanced centrifuges
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It had also "intimidated international inspectors into not using the full inspection authorities that the agreement calls for"
Iran, he said, was spreading "death, destruction and chaos".
It was "not living up to spirit of the deal", he said, but was receiving the benefit of sanctions relief regardless.
His new strategy would fix that, he said. He said that the US reserved the right to leave the deal at any time.
Within minutes of his address, EU's foreign policy chief Federica Mogherini insisted the deal was "robust" and that there had been "no violations of any of the commitments in the agreement".
She said it was not in the power of "any president in the world" to terminate the agreement, which had been established by a UN Security Council resolution.
Trump had been under pressure at home and abroad not to scrap the deal between Iran and the US, UK, France, China and Russia plus Germany.
He also focused on Iran's non-nuclear activities, particularly those of the Revolutionary Guards, which he called the "corrupt personal terror force of Iran's leader".
Trump said he would impose sanctions outside the Iran deal targeting both the Guards and "the proliferation of missiles that threaten global trade and freedom of navigation".
A key criticism of the Iran deal by Trump has been that it fails to cover Iran's ballistic missile programme.
--IANS
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