WASHINGTON-Treasury Secretary Scott Bessent said the U.S. is launching a new campaign to isolate the Iranian regime, warning that countries and companies that do business with Tehran will face the wrath of the Trump administration.

"Let there be no ambiguity as to the position of the United States: An economic engagement of any kind with this murderous regime will expose those responsible to the full reach of American power," Bessent said Monday during a press conference.

As part of the new effort, which he called "Operation Economic Outcast," Bessent said his department has "mapped every node, every facilitator and every network that Iran has used to smuggle oil and evade sanctions." He said the U.S. was sanctioning more than 60 entities, individuals and vessels across the world that enable the regime to procure nuclear and missile technology, earn revenue from oil and carry out cyber operations.

The U.S. has already imposed a blockade against Iranian ports and commerce, which is squeezing Tehran's weak economy. With Iran's currency recently dropping to a record low against the dollar, President Trump said on social media on Monday that Iran is "completely collapsing."

Top Iranian officials said the new effort would be ineffective.

Bessent didn't outline any specific steps the U.S. would take against individual countries-including China, a major buyer of Iran's oil. He said the U.S. privately defined timelines for countries to comply, telling reporters: "I'm not going to set timelines, but we do not have infinite patience here."

After the press conference, the Treasury Department announced that secondary sanctions could apply to countries and entities that do business in five sectors: digital assets, technology, gold, aviation and shipping. Treasury officials also suspended several general licenses for remittance payments and provided more sanctions-risk guidance to those who comply with Iran's demands in the Strait of Hormuz.

Last week, Bessent said the aim of the new policy would be to create the conditions for "regime collapse." The ambiguity in Monday's announcement leaves open the question of whether the campaign will achieve his goal of executing the largest-ever economic-isolation campaign.

Bessent did give a few specific examples of action the U.S. will take. He said the U.S. will push other countries to shutter foreign branches of Bank Melli, Iran's state-owned biggest bank, which has branches in several European countries.

He said there would be an announcement this week of sanctions against a financial institution, as well as new steps to restrict aviation and shipping links with Iran and prevent trade in gold and digital currencies.

Trump, he said, is making phone calls to world leaders to request they stop doing business with Iran.

Shortly before Bessent spoke, Iran's top negotiator, parliament speaker Mohammad Bagher Ghalibaf, said the new U.S. measures would fail. "Americans know that no one buys their bombast," he said on social-media platform X. "Iran's trading partners, both in the media and through messages sent to us, have made it clear that they don't take these statements into account anywhere."

The announcement comes as the U.S. has struggled to bring the war with Iran to an end. The U.S. and Iran have so far failed to reach an agreement to fully reopen the Strait of Hormuz and force Tehran to curb its nuclear ambitions.

In recent weeks, the U.S. has shifted focus from its military operation to a campaign against Iran's economy. Trump has described the new sanctions as "economic D-Day" for Iran. Iran is already one of the world's most sanctioned countries after previous attempts to weaken it through economic means, including Trump's first-term "maximum pressure" campaign.

Notably, Bessent didn't mention China, the regime's top trading partner, in his opening remarks about countries being targeted by the Treasury Department.

"We want to make clear here today that no one is above the reach of the U.S. sanctions," Bessent said when asked whether the U.S. would sanction Chinese banks that do business with Iran.

China's large-scale purchases of Iranian oil add billions of dollars to Tehran's coffers annually. It buys about 90% of the oil that Iran exports.

While the U.S. blockade of Iranian ports and commerce may mean China isn't currently buying much Iranian oil, Chinese banks and other entities are still involved in repatriating revenues to Tehran.

The Trump administration came into office vowing to tighten and broaden sanctions to further squeeze the Iranian economy, even as the White House reached out to Tehran to start talks. It pledged to drive Iranian oil exports to zero, but China's purchases from Iran didn't slow.

The failure of that effort underscores the central dilemma the U.S. will face in any sweeping new sanctions effort: Washington will need to give priority to a country's economic ties with Iran above other interests, and it will have to risk counter-sanctions if it penalizes foreign firms in countries like China.

Trump has made improved relations between the U.S. and China a priority following a major tariff war and fights over access to rare earths, issues which dominated the bilateral relationship for much of the last 18 months. Trump in May visited Xi Jinping in Beijing, and the Chinese leader is expected in Washington next month for a follow-up summit.