Foreign Minister Hossein Amir-Abdollahian's comments came a day after the US pointman on Iran, Rob Malley, said the odds of success were lower than the odds of failure.

"The most important thing is that the economic sanctions need to be lifted in an effective way. The most important thing is that the maximum pressure policy of the Trump era... needs to be removed," Amir-Abdollahian said at the World Economic Forum in Davos, Switzerland.

"If you are talking about direct talks then you have to prove to us that you're different from President Trump," he said.

The 2015 agreement gave Iran sanctions relief in exchange for curbs on its nuclear programme to guarantee that Tehran could not develop a nuclear weapon -- something it has always denied wanting to do.

But the US unilateral withdrawal from the accord in 2018 under then-president Trump and the impositon of biting economic sanctions prompted Iran to begin rolling back on its own commitments.

On Wednesday the US Treasury Department said it was imposing sanctions on a network backed by Iran's Revolutionary Guards and Russian officials that has shipped hundreds of millions of dollars of oil in defiance of unilateral US sanctions.

Iran's foreign ministry spokesman Saeed Khatibzadeh called the new sanctions a "continuation of the same failed policy" adopted by Trump, and a "sign of the US government's ill will toward the Iranian people".

"The Islamic Republic of Iran reserves the right to take appropriate and decisive action against these measures in accordance with the principles of international law," he added in a statement.

Malley, who has led more than a year of indirect talks with Iran in Vienna, said Wednesday that Trump's approach had demonstrably failed, with Iran stepping up nuclear work since the United States withdrew from the deal.

He told US lawmakers that Biden's administration still supported the 2015 accord and was ready to lift sanctions if it secures an agreement.

But he said "excessive Iranian demands" made the odds of success lower.