If the Americans have "true intentions, let them release some of our assets, for example $10 billion frozen in foreign banks", Hossein Amir-Abdollahian said in an interview with state television broadcast late Saturday.

"But the Americans are not prepared to unlock them for us to be assured that they've taken into account the interests of the Iranian people at least this one time over the past decades," he said.

On Thursday, US Secretary of State Antony Blinken renewed warnings that time was running out for Iran to return to the 2015 nuclear deal between Tehran and world powers.

"The ball remains in their court, but not for long," Blinken told reporters. "There is a limited runway on that, and the runway is getting shorter."

Blinken reiterated that President Joe Biden was willing to return the United States to the accord in which Iran drastically scaled back nuclear work in return for promises of economic relief.

Former president Donald Trump withdrew from the deal and reimposed sweeping sanctions, which Iran wants removed before it undoes a series of steps out of compliance that it took to protest the pressure campaign.

The Biden administration had been engaged in indirect talks in Vienna with Iran on returning to compliance.

Iran requested a break in talks in June due to a political transition as the ultraconservative Ebrahim Raisi took over as president.

The parties to the 2015 deal with Iran saw it as the best way to stop the Islamic republic from building a nuclear bomb -- a goal Tehran has always denied.