Trump withdrew from the Iran deal stating "It was a bad deal. Worst deal in history."
France, Germany and the UK have said they "regret" the American decision. The foreign ministry of Russia, another signatory, said it was "deeply disappointed".
The European Union's top diplomat, Federica Mogherini, said the EU was "determined to preserve" the deal.
The United Nations secretary general's spokesman said Antonio Guterres was "deeply concerned" at the announcement and called on the other signatories to abide by their commitments.
Iran has stated the would resume their nuclear program if a deal was not met. To this, Trump responded:
"I would advise Iran not to start their nuclear program," Trump told reporters at the start of a Cabinet meeting when asked about the potential consequences. "I would advise them very strongly. If they do there will be very severe consequence."
Can the Iran deal still be salvaged by other western nations?