The Trump administration has vowed to aggressively enforce economic sanctions being reimposed on Iran aimed at further crippling the nation’s economy.
The so-called snapback sanctions, due to come into force later on Tuesday, target Iranian purchases of US dollars, metals trading and other dealings, coal, industrial-related software and its auto sector.
Iran’s rial currency has lost half its value since April under the threat of revived US sanctions.
President Donald Trump is aiming to cut off the Iranian leadership’s access to resources, senior US administration officials said on Tuesday morning (AEST).
The US also plans to reintroduce potentially more damaging sanctions on Iranian oil in November.
The US sanctions strategy has several weak spots, especially a reluctance by Europe and China to curtail business with Iran.
The EU voiced concern in a joint statement with the foreign ministers of France, Germany and Britain, saying: “We deeply regret the reimposition of sanctions by the US.”
Mr Trump warned of “severe consequences” for people or entities that fail to wind down economic activities with Iran.
“The United States is fully committed to enforcing all of our sanctions, and we will work closely with nations conducting business with Iran to ensure complete compliance,” he said in a statement.
But White House national security adviser John Bolton said if Iran wanted to avoid sanctions, it should take up Mr Trump’s offer to negotiate.
Mr Bolton told Fox News that Iran’s leaders could “take up the President’s offer to negotiate with them, to give up their ballistic missile and nuclear weapons programs fully and really verifiably, not under the onerous terms of the Iran nuclear deal, which really are not satisfactory”.
“If Iran were really serious they’d come to the table. We’ll find out whether they are or not,” he said.
The sanctions being brought back were among those lifted under the 2015 deal between world powers and Tehran on curbing Iran’s nuclear program.
The sanctions aim to modify Iran’s behaviour and not bring about a “regime change” targeting President Hassan Rouhani, US officials said.
They said the Iranian government’s handling of social and labour protests was a concern.
One EU measure to mitigate the impact of US sanctions, known as the blocking statute, will come into force on Tuesday.
US officials said Mr Trump was ready to meet Iran’s leaders at any time to try to forge a new agreement.