The United States is expanding its military presence around Iran and has announced a new round of sanctions, even as Tehran says it remains open to talks to end the seven-month war.

An unnamed US official told reporters on Thursday that the aircraft carrier USS Theodore Roosevelt and its accompanying warships have left San Diego for the Middle East.

A Marine expeditionary force of more than 2,000 personnel left the same base earlier this week. By the end of November, the official said, Washington expects to have three aircraft carriers and two amphibious groups deployed around Iran.

The official said that concentration of force would give the US “many options” in dealing with Tehran.

The US Treasury also announced new sanctions on Thursday under its “Operation Economic Outcast” campaign. They target Iran’s two biggest car makers, Iran Khodro and SAIPA, along with several rail companies and the country’s manufacturing and steel sectors.

Foreign suppliers and facilitators in the UAE, Turkiye, Hong Kong, Indonesia, Germany and China were also designated. The measures freeze US-linked assets of those named and generally bar American persons from dealing with them, and some foreign banks could face secondary sanctions.

Treasury Secretary, Scott Bessent said the action was meant to cut Iran’s remaining revenue sources and industrial networks. Earlier this week, Washington sanctioned ten individuals and entities in Iran, Hong Kong and Pakistan over accusations that they procured weapons and components for Iran’s defence ministry.

In a separate move, US Ambassador to the UN Mike Waltz said Washington will set up its own panel to monitor enforcement of Iran sanctions. This follows a Russian and Chinese veto on September 17 of a Security Council resolution that would have extended the mandate of UN experts monitoring the sanctions.

Moscow has argued that the snapback process that reimposed the sanctions has no legal basis.

Tehran has pushed back on the pressure. President Masoud Pezeshkian said Iran has never avoided dialogue with the United States, even though it has been attacked three times during negotiations.

Acting defence minister, Majid Ebn-e-Reza dismissed US claims that Iran’s defence industry has been destroyed, saying Iran’s capabilities would be seen on the battlefield. Iran’s economy minister also said the economy will not collapse within weeks, as some forecasts have suggested.

The latest moves come after President Donald Trump rejected an Iranian proposal that reportedly called for the lifting of the US blockade of Iranian ports, the release of frozen assets and waivers on oil sales. Trump said the offer was not acceptable. Iranian officials said on Wednesday that they had received a US reply to their latest proposal, without disclosing what it contained.

Mediators are reportedly still working to broker a deal that would end the fighting and reopen the Strait of Hormuz.