US President Donald Trump on Monday signed an executive order to enforce UN sanctions on Tehran as his administration announced penalties on Iranian-linked people and entities.
The executive order follows resistance from allies and the UN to US reinstate sanctions lifted under the 2015 Iran nuclear deal and extend a UN arms embargo set to expire next month.
“I am issuing a new executive order, restoring UN sanctions on Iran, and imposing new sanctions and export controls on more than two dozen entities and individuals that support Iran’s nuclear, missile and conventional arms-related activities,” Mr Trump said.
He pledged not to allow Iran to have an atomic weapon, two years after pulling the US out of the nuclear deal between Tehran and world powers.
“My administration will never allow Iran to have a nuclear weapon, nor will we allow Iran to endanger the rest of the world with a fresh supply of ballistic missiles and conventional arms,” Mr Trump said.
Only minutes earlier, the Treasury and State Departments announced sanctions on 27 entities and people connected to Iran’s weapons networks.
“Rather than waiting for Iran to threaten the world, the US is taking sweeping actions to prevent the world’s top state sponsor of terror from obtaining a nuclear weapon,” Secretary of State Mike Pompeo said in a tweet.
Mr Pompeo was joined by Treasury Secretary Steve Mnuchin, Defence Secretary Mark Esper, National Security Adviser Robert O’Brien, UN ambassador Kelly Craft and Commerce Secretary Wilbur Ross to announce the sanctions, which included Iran's Defence Ministry.
Mr Esper said the US was ready to respond to Iranian aggression as the Treasury designated key producers and suppliers of military-grade items for Iran's ballistic missile programme.
Three deputy directors from Iran's Atomic Energy Organisation also had sanctions imposed.
They included Mohammad Maragheh, deputy head of nuclear planning and strategic supervision, and Javad Sabet, head of the agency's Nuclear Science and Technology Research Institute.
Mr Ross said that five Iranian scientists were added to the sanctions list.
Two people with sanctions were central to Iran’s uranium enrichment operations, Mr Pompeo said.
Iran broke nuclear enrichment and stockpile limits after the US pulled out of the nuclear deal.
Mr Pompeo notified the Security Council last month that the US was triggering a 30-day "snap back" process to restore UN sanctions on Iran by September 19.
But other Security Council members dispute that the US can invoke the "snapback" clause, which is part of the nuclear deal, after leaving the agreement.
Britain, France and Germany said the US announcement "is incapable of having legal effect”.
UN Secretary General Antonio Guterres said the uncertainty was preventing him from acting on the US declaration.
In a letter to the Security Council, Mr Guterres said there would be no snapback sanctions on Iran without approval.
“The Security Council has taken no action subsequent to the receipt of the letter of the US secretary of state, neither have any of its members or its president,” he wrote.
"It is not for the secretary general to proceed as if no such uncertainty exists.”
Ms Craft said on Monday that she expected every single UN member state would reimpose sanctions on Iran. Mr Trump is due to address the UN General Assembly on Tuesday.
Mr Pompeo said that if countries failed to act, "the United States is prepared to use our domestic authorities to impose consequences for those failures”.
Eliott Abrams, the US special representative on Iran and Venezuela, said the sanctions also aimed to counter Iran’s support for the Houthis in Yemen and Hezbollah in Lebanon.
“Iran still uses its arsenal of weapons to foment instability across the Middle East,” Mr Abrams said.
He said the new sanctions would target anyone selling arms to Iran and shrugged off criticism describing the US as isolated and unilateral sanctions as ineffective.
“After the snapback sanctions went into effect on Saturday, the Iranian rial fell to its lowest ever,” Mr Abrams said.
He said the 2015 deal left a way for a nuclear weapon for Iran through artificial deadlines that would later expire.
The US is open to diplomacy but Tehran first had to stop supporting terrorism and promoting anti-Semitism, Mr Abrams said.