US Treasury Secretary Scott Bessent threatened Thursday to subject Iran to economic isolation "like the world has never seen before," adding that new measures are expected next week.
"It will be a combination of economic isolation, like the world has never seen before," Bessent told conservative television network Newsmax, adding that "the continued blockade in the Strait of Hormuz... will keep anything from going in or out of the Iranian ports."
"Watch this space for more announcements coming next week," he said.
Bessent described a two-pronged approach featuring financial pressure and a physical blockade of the ports.
The tougher stance contrasts with remarks by Bessent on 4 August, when he told CNBC that an agreement with Tehran to reopen the Strait of Hormuz could be reached within days.
Those comments sent Wall Street higher and oil prices lower.
Meanwhile, Vice President JD Vance said earlier that the top US priority in the US-Israeli war on Iran presently was bringing oil and gasoline prices down for Americans, with preventing Tehran from acquiring a nuclear weapon ranking second.
Vance's comments underscored the stark reality that the war now centers on control of the Strait of Hormuz, the critical fuel supply conduit that was open before US President Donald Trump started the war along with Israel in late February.
Iran has all but shut it down in retaliation and thus found a crucial bargaining chip against Trump as he struggles to find a way out of the war and shies away from resuming large-scale attacks.
The 80-year-old president's approval rating is plummeting, the war is unpopular among Americans and midterm elections are approaching in November.
Republicans fear Trump and the war, which has caused gasoline prices to soar, will cost them their control of Congress.
"I know that oil is down today and it's way down from the highs in the early days of the conflict," Vance said on Fox News. "That's goal number one -- keep oil and gas cheap for Americans all over our country."
"And then obviously goal number two is ensure that Iran never gets a nuclear weapon," he added.
'Low-keying it'
The vice president has been among the members of the administration most skeptical of the offensive launched against Iran in late February.
These remarks, however, appear to confirm the more cautious approach now favored by the US president, which involves maintaining strong economic pressure on Iran by blockading its ports and preventing it from selling oil.
Heralding more economic punishment, Bessent threatened to subject Iran to economic isolation "like the world has never seen before." He said new measures are expected next week.
Only days ago Trump had said an agreement to reopen the strait was imminent. Now his administration seems to be digging in, with diplomacy on hold as he hopes economic suffering will cause Iran to yield.
"We are low-keying it," Trump said Sunday. "We are only semi-negotiating with them. We are just watching Iran with its huge inflation and the fact they have no money," Trump told the news outlet Axios.
The US military reportedly burned through stockpiles of costly high-tech missiles and other weapons in the months since the war started at a cost of billions and is now reportedly running low, limiting Trump's options for resuming attacks on Iran.
"Sometimes we're focused on the energy piece of it because we want Americans to be able to afford the price of oil and gas. Sometimes we're obviously focused on the military... on the nuclear program," Vance also said.
Trump had said recently he would hold off on attacking Iran again only if an agreement were reached quickly to reopen the Strait of Hormuz.
Now Iran has set a list of conditions for reopening the passageway that the Trump administration is unlikely to accept: an end to the war on all fronts, the lifting of the US blockade of Iranian ports, the end of sanctions, the release of frozen assets and compensation for wartime damage.
Those conditions echo the terms of a so-called memorandum of understanding which was reached in June and collapsed as fighting resumed. It included a provision to create a $300 billion reconstruction fund for Iran.