European powers scrambled Wednesday to save a landmark deal curbing Iran's nuclear programme after President Donald Trump pulled the United States out of the agreement and reimposed sanctions on Tehran.
Trump sparked an international outcry by ditching the accord, a move that risks overturning years of diplomacy and adding to instability in the Middle East.
Trump poured scorn on the "disastrous" 2015 accord in an address to the nation from the White House on Tuesday.
He described it as an "embarrassment" to the US that does nothing to contain Iran's nuclear ambitions.
In response, the foreign ministers of France, Britain and Germany will meet with Iranian representatives next Monday "to consider the entire situation," France's Foreign Minister Jean-Yves Le Drian told RTL radio.
French President Emmanuel Macron will also speak with his Iranian counterpart Hassan Rouhani by telephone on Wednesday afternoon about "our wish to stay in the agreement," Le Drian said.
He added that European powers would "try to preserve" the economic benefits Iran has gained from the lifting of sanctions under the deal.
In separate comments, French Economy Minister Bruno Le Maire said that it was "not acceptable" for the US to be the "economic policeman of the planet".
Slapping aside more than a decade and a half of diplomacy by Britain, China, France, Germany, Iran, Russia and past US administrations, Trump called for a "new and lasting deal".
He said that would have to include not just deeper restrictions on Iran's nuclear programme, but on its ballistic missiles and support for militant groups across the Middle East.
"We cannot prevent an Iranian nuclear bomb under the decaying and rotten structure of the current agreement," he claimed.
"We will not allow American cities to be threatened with destruction and we will not allow a regime that chants 'Death to America' to gain access to the most deadly weapons on Earth."
Iran's Rouhani -- whose standing at home now risks being undermined by the deal's collapse -- was furious, accusing Trump of "psychological warfare".
Rouhani said Iran could resume uranium enrichment "without limit" in response to Trump's announcement, but that it would discuss its response with other parties to the deal before announcing a decision.
Trump's demands and his warning that Iranians deserve better than their current "dictatorship" will fuel suspicions that his ultimate goal is regime change.
"If the regime continues its nuclear aspirations, it will have bigger problems than it has ever had before," he warned.
The decision marked a stark diplomatic defeat for Europe, whose leaders begged the US leader to think again.
In a joint statement, Germany's Angela Merkel, Britain's Theresa May and France's Macron voiced their "regret and concern" at Trump's decision.
European firms doing business in Iran now have a six month deadline to wind up investments, or risk US sanctions, Trump's advisor John Bolton said.
Treasury Secretary Steven Mnuchin said Washington was acting "under both our primary and secondary sanctions authorities".
That meant that European firms with investments or operations in the United States could be targeted if they continue to trade with Iran.
Plans are already being drawn up in Brussels to introduce measures blocking US sanctions -- an extremely rare move against an allied government.
But Bolton said that cooperation with Europe on Iran was not over.
The US will "work with the Europeans and others not only on the nuclear issue but on Iran's ballistic missile development, its continuing support for terrorism and its military activities that jeopardise our friends," Bolton told Fox News.
While Iran's arch foes in Israel and Saudi Arabia welcomed Trump's decision, signatories to the existing deal vowed to plough ahead without the US.
The European Union's chief diplomat Federica Mogherini, who helped oversee the accord, insisted it was "delivering on its goal which is guaranteeing that Iran doesn't develop nuclear weapons."
"The European Union is determined to preserve it," she added.
Trump's decision offers him a domestic political victory, fulfilling a longstanding campaign promise.
But the long term impact for US foreign policy and for the Middle East was less clear.
Some analysts also warned the move would complicate US efforts to reach an agreement with North Korean leader Kim Jong Un over his country's own more advanced weapons programme.
Former CIA director John Brennan said Trump's move "gave North Korea more reason to keep its nukes".
Former US president Barack Obama -- whose administration inked the deal -- made a rare public criticism of his successor.
"The consistent flouting of agreements that our country is a party to risks eroding America's credibility, and puts us at odds with the world's major powers," he said.
Elsewhere, Russia's foreign ministry said it was "deeply disappointed" by the decision.
And a spokesman for Turkish President Recep Tayyip Erdogan, Ibrahim Kalin, warned on Twitter that Trump's move "will cause instability and new conflicts".
But Israeli Prime Minister Benjamin Netanyahu strongly supported the move.