The US on Thursday sanctioned a network of Iranian petrochemical firms, as well as alleged front companies in China and the United Arab Emirates, accusing them of helping Tehran to circumvent sanctions.

"I am surprised (by the behaviour) of the Americans," Raisi said, quoted by the official news agency IRNA.

"On the one hand, they send a message in favour of negotiations and agreement, and on the other hand, they lengthen the list of sanctions.

"I don't understand how this works," the Iranian president said.

Iran disconnected some International Atomic Energy Agency cameras monitoring its nuclear sites this month, shortly after the US and its European allies pushed through a resolution at the IAEA denouncing Iran's lack of cooperation.

"The world must give us the right not to trust the United States because they are violating their agreements," Raisi said.

The 2015 deal gave Iran relief from sanctions in return for guarantees that it could not develop a nuclear weapon -- something Tehran has always denied wanting to do.

The United States unilaterally withdrew from the nuclear deal in 2018 under then president Donald Trump, before imposing waves of biting sanctions on the Islamic republic.

On Tuesday, Iran's Foreign Minister Hossein Amir-Abdollahian said he still believed the nuclear negotiations could succeed and that diplomacy was one of the best ways to revive the accord.