"We will apply unprecedented financial pressure on the Iranian regime. The leaders in Tehran will have no doubt about our seriousness," Pompeo said in his first major foreign policy address since moving to the State Department from the CIA.

"The sting of sanctions will only grow more painful if the regime does not change course from the unacceptable and unproductive path it has chosen for itself and the people of Iran," he added in the speech at the conservative Heritage Foundation think tank.

"Iran will never again have carte blanche to dominate the Middle East," he said in outlining the new US strategy on handling the Islamic regime, including 12 tough conditions from Washington for any "new deal" with Tehran.

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 sanctions.

"We will track down Iranian operatives and their Hezbollah proxies operating around the world and crush them," Pompeo said.

"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."

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.

"In the strategy we are announcing today, we want the support of our most important allies and partners in the region and around the globe. I don't just mean our friends in Europe," Pompeo said.

The secretary of state also warned European businesses who work with Iran in violation of US sanctions that they will be held "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 Washington's participation.