US Secretary of State Mike Pompeo announced a new high-level team to focus US and international efforts to increase diplomatic and economic pressure on Iran.
The Iran Action Group will drive Washington's "maximum pressure" strategy to change Tehran's behavior, including potentially sanctioning other countries which trade with the country.
The group will be headed by Brian Hook as the State Department's Special Representative for Iran.
Hook, currently director of policy planning at the State Department, was in charge of the failed effort to get support from US allies for Washington's decision in May to pull out of the Iran nuclear deal.
"For nearly 40 years the regime in Tehran has been responsible for a torrent of violence and destabilizing behavior against the United States, our allies, our partners and indeed the Iranian people themselves," said Pompeo.
"Our hope is that one day soon we can reach a new agreement with Iran. But we must see major changes in the regime's behavior both inside and outside its borders."
The US has laid out a long list of activities it demands Tehran changes, including halting support for the Syrian government and the Lebanese Hezbollah movement, shutting down its nuclear development program, and freeing detained Americans.
"This team is committed to a strong global effort to change the Iranian regime's behavior," Hook said.
"We want to be closely synchronized with our allies and partners around the world."
Hook, who met with officials from Britain, France and Germany on Iran policy in London on Wednesday, held out the possibility of the US engaging directly with Iranian leaders if they demonstrate a "commitment" to changing their behavior.
But he was not specific on what would be the minimum required to make that impression.
He also said that Washington is stepping up its effort to get other countries to fall in line with economic pressure on Tehran, including the crackdown on Iran's oil trade, financial sector and shipping industry announced for early November.
"Our goal is to reduce every country's import of Iranian oil to zero by November 4."
"We are prepared to impose secondary sanctions on other governments that continue this sort of trade with Iran."
Last week Trump warned the world about doing business with Iran, as European allies continued to grumble about the US policy and China, India and Turkey appeared poised to continue importing Iranian oil, providing the Iranian government crucial foreign exchange.
But the US sanctions appear to have had effect, tightening the country's supply of dollars and sending its currency in a tailspin -- with the result a jump in inflation that has hurt Iranian consumers.
In Monday Iran's supreme leader Ayatollah Ali Khamenei's said there would be neither war nor negotiations with the United States, and put the blame for mounting domestic economic turmoil on the shoulder of President Hassan Rouhani.
US officials have repeatedly said they only pressuring for a change in Iranian behavior and not change in the regime itself.
Asked whether the announcement of the Iran Action Group was purposely timed with 65th anniversary of the CIA-engineered overthrow of ex-prime minister Mohammad Mossadegh -- which took place in mid-August 1953 -- Hook labelled it "pure coincidence."