US Secretary of State Mike Pompeo issued a severe warning to Iran on Monday, saying Washington would be ready to impose the “strongest sanctions in history” if it does not alter its regional policies. In his first major foreign policy address since moving to the State Department from the CIA, the longtime Iran hawk and ardent opponent of the 2015 nuclear pact outlined an aggressive series of moves designed to counter Tehran, which he called the worlds top sponsor of terror. "Irans leaders saw the deal as a starting gun for the march across the Middle East," Pompeo said. Pompeo said the bet the deal would increase Middle East stability had been a bad one for America, Europe, the Middle East "and indeed for the entire world." "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 rejoins the league of nations." Pompeo said if Iran were to abide by the stricter terms, including ending its ballistic missile program and its interventions in regional conflicts from Yemen to Syria, the United States would lift its new sanctions. "Iran will be forced to make a choice: either fight to keep its economy off life support at home or keep squandering precious wealth on fights abroad. It will not have the resources to do both," he said. Pompeo also cautioned European firms against continuing to do business in Tehran, toughening up Washingtons policy line after its withdrawal from the nuclear pact. President Donald Trump has long said the original 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 hardline 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 behavior not covered in the pact, and on May 8 he pulled America out despite intense diplomatic efforts 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." These essentially address every aspect of Irans missile program and what the US calls its "malign influence" across the region, including support for Syrian regime leader Bashar al-Assad, Lebanon’s “Hezbollah” and Houthi militias in Yemen. "It must cease its threatening behavior against its neighbors," Pompeo said. "This certainly includes its threats to destroy Israel, and its firing of missiles into Saudi Arabia" and the United Arab Emirates, he added. He said Iran must "stop enrichment" of uranium and never preprocess plutonium. Iran must also allow nuclear "unqualified access to all sites throughout the country." Iran must also "release all US citizens" missing in Iran or being held on "spurious charges," he added. Laying out Trumps new approach, Pompeo said he could not put a timeline on how long the strategy might take. "At the end of the day, the Iranian people will get to make their choice about their leadership," Pompeo continued. "If they make the decision quickly, that would be wonderful. If they choose not to do so, we will stay hard at this until we achieve the outcomes that I set forward today." "It is Americas hope that our labors toward peace and security will bear fruit for the long-suffering people of Iran," Pompeo stressed. European allies heard how he expects their support for the new US plan -- but he offered nothing in return, and threatened economic fallout for anyone still dealing with Iran. "We understand that our re-imposition of sanctions and the coming pressure campaign on the Iranian regime will pose financial and economic difficulties for a number of our friends," he said. "We want to hear their concerns. But you know, we will hold those doing prohibited business in Iran to account." The re-establishment of the US sanctions will force European companies to choose between investing in Iran or trading with the United States. In reality, there is no choice -- European companies cannot afford to forsake the US market. For now, the European Union is trying to persuade Iran to stay in the 2015 agreement, even without Washingtons participation.