It left European Union foreign policy chief Federica Mogherini and the foreign ministers from Britain, France and Germany - signatories of the 2015 deal to stop Iran developing nuclear weapons - with their backs against the wall as they prepared for a dinner meeting with Iranian Foreign Minister Mohammad Javad Zarif.
Federica Mogherini, who negotiated the deal on behalf of the European Union, listed a string of proposals that taken together may not be enough to convince Iran's leaders to hold to the deal but probably will be seen in Washington as a raised fist against US policy. It also came over the opposition of China and Russian Federation, which are also party to the 2015 deal.
"If we achieve the deal's goals in co-operation with other members of the deal, it will remain in place", Iranian President Hassan Rouhani said.
Upon withdrawing, President Trump described it as a "horrible, one-sided deal that should have never, ever been made".
Iranian Foreign Minister Javad Zarif speaks with the media after a meeting with European Union foreign policy chief Federica Mogherini at the Europa building in Brussels, May 15, 2018.
Whatever course the negotiations take, the move is likely to have major repercussions for Iran, the region and for worldwide cooperation.
"Our governments remain committed to ensuring the agreement is upheld", the leaders said, "including through ensuring the continuing economic benefits to the Iranian people that are linked to the agreement".
She said she would brief the weekly meeting of the College of the European Commission on Wedneday morning and address European leaders about the results of Tuesday's talks on Wednesday evening.
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Zarif is in Brussels on the final leg of a whirlwind diplomatic tour to save the 2015 nuclear deal after the recent USA withdrawal from the pact.
She told reporters it was a positive meeting.
France, he said, is "totally determined" to "make our economic interests respected and to respect one principle, which is the refusal of extra-territorial sanctions".
The impact of the reintroduction of sanctions is not going to be limited to Iran alone; it will also hurt the European countries who have already resumed lucrative business with the oil-rich country.
As Javier Blas, a chief energy correspondent at Bloomberg News, noted in his tweet, "France is floating European financing tools to bypass United States sanctions on Iran (including ideas to use the European Investment Bank, the European Central Bank or ad-hoc instruments to trade)".
British Foreign Secretary Boris Johnson warned Tuesday that Washington's sanctions may be able to strike around the world because of the long reach of the USA financial system. While Iran's GDP did improve after the lifting of sanctions, unemployment has continued to take a toll on living standards. Roughly 120 German firms operate in Iran, and almost 10,000 German companies trade with Iran.
Not only has Trump's walkout of the deal imperiled its future, the threat of sanctions could also trickle down to European companies doing business with Iran and further hurt trans-Atlantic ties. It's meant to be a 20-year project and Total's investments are believed to be $5 billion. To that end, the so-called E-3, Germany, France and the United Kingdom, will meet with Iranian officials over the coming two weeks.
Mr Johnson revealed on Monday that he would discuss ways to protect them during a meeting with fellow foreign ministers from France and Germany on Tuesday.
A French government official told reporters earlier this week that the USA practice of punishing foreign companies operating in foreign countries like Iran "is a real problem".