"The United States has just introduced a new package of sanctions affecting the mining industry in Iran. We strongly condemn this step," the foreign ministry said in a statement.

Because of the "seriousness of what is happening," Iran and world powers should meet "to determine ways to normalise the situation," the ministry said.

Moscow said it understood why Iran, in the face of US sanctions, had decided to suspend some of its commitments under the deal.

But it urged Tehran to "refrain from further steps to curtail the fulfilment of its obligations", while calling on other partners in the deal to meet their promises.

Among the steps that needed to be taken, it said, were moves to facilitate financial transactions and to continue trade and economic cooperation.

"We urge everyone not to cut off economic ties, including the purchase of Iranian products, first of all energy."