US Secretary of State Mike Pompeo on Monday warned Tehran would be hit with the "strongest sanctions in history" and cautioned European firms against continuing to do business with it, toughening up Washington's policy line after its withdrawal from the Iran nuclear deal.
In his first major foreign policy address since moving to the State Department from the CIA, the long-time Iran hawk and ardent opponent of the 2015 nuclear pact outlined an aggressive series of moves designed to counter Tehran, which he called the world's top sponsor of terror.
"We will apply unprecedented financial pressure on the Iranian regime. The leaders in Tehran will have no doubt about our seriousness," Pompeo said in a speech at the conservative Heritage Foundation think tank.
"This sting of sanctions will be painful if the regime does not change its course from the unacceptable and unproductive path it has chosen to one that re-joins the league of nations."
Iranian President Hassan Rouhani quickly dismissed the threats, saying the rest of the world no longer accepts Washington making decisions on their behalf.
"Who are you to decide for Iran and the world?" Rouhani said in a statement carried by multiple Iranian news agencies.
"The world today does not accept that the United States decides for the world. Countries have their independence," he added.
Pompeo said if Iran were to abide by stricter terms, including ending its ballistic missile programme and its interventions in regional conflicts from Yemen to Syria, the US would lift its new sanctions.
US President Donald Trump has long said the 2015 deal with Iran - also signed by Britain, China, France, Germany and Russia - did not go far enough, and now wants the Europeans and others to support his hard-line strategy.
The deal was designed to prevent Iran from developing a nuclear weapon. The international community, including top US officials, have said Tehran had been in compliance.
But Trump despised the deal, pointing to other aspects of Iranian behaviour not covered in the pact, and on May 8 he pulled America out despite intense diplomatic lobbying by European allies who had beseeched him to stick with it by adding tougher new elements.
Instead of suggesting a re-negotiation of the Iran deal, Pompeo outlined 12 tough conditions from Washington for any "new deal" with Tehran to make sure it "will never again have carte blanche to dominate the Middle East".
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