Europe's heavyweight economies took steps on Friday to safeguard their commercial and political interests in Iran, seeking to keep the nuclear deal with Tehran alive after Washington pulled out and said sanctions would follow.
Germany, France have significant trade links with Iran and remain committed to the nuclear agreement, as does Britain, and all three countries' foreign ministers plan to meet on Tuesday to discuss it.
That is part of a flurry of diplomatic activity lined up following Tuesday's unilateral withdrawal from what U.S. President Donald Trump called "a horrible, one-sided deal", a move accompanied by the threat of penalties against any foreign firms doing business in Iran.
German Chancellor Angela Merkel said possibilities to save the deal without Washington needed to be discussed with Tehran, while France's Finance Minister Bruno Le Maire said EU states would propose sanctions-blocking measures to the European Commission.
"There is a realisation among all European states what we cannot keep going in the direction we are headed today whereby we submit to American decisions," Le Maire told reporters in Paris.
In Berlin, Economy Minister Peter Altmaier said Germany was ready to give help to its affected firms, including legal advice, to continue doing business in Iran.
Foreign Minister Heiko Maas said transatlantic ties had been gradually damaged by shifts in U.S. policy. "We are prepared to talk... but also to fight for our positions where necessary," he told Der Spiegel magazine.
Europeans fear a collapse of the nuclear deal could raise the risk of deepening conflicts in the Middle East.
Germany, France and Britain want talks to be held in a broader format on Iran's ballistic missile programme and its regional military activities, including in Syria and Yemen.
"The extent to which we can keep this deal alive ...is something we need to discuss with Iran," said Merkel, who earlier spoke with Russian President Vladimir Putin on the issue.
Divisions in Iran over what should happen next were illustrated as senior cleric Ayatollah Ahmad Khatami told worshippers at Tehran University on Friday that European nations could not be trusted.
President Hassan Rouhani had said on Tuesday that Tehran would remain in the deal, provided its benefits stayed in force under its remaining signatories.
Iran's foreign minister will travel to Moscow on May 14 and meet his Russian counterpart, Russia's RIA news agency said, citing a Russian foreign ministry official.