FILE PHOTO: French President Macron and German Chancellor Merkel wave after Macron was awarded Charlemagne Prize in Aachen Thomson Reuters By Paul Carrel and Richard Lough

BERLIN/PARIS (Reuters) - 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 realization 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 program 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.

"DAMAGE LIMITATION"

Iran said it had asked Europe's Airbus to announce whether it would go ahead with a plane deal with Tehran following the U.S. pullout.

That appears unlikely after U.S. Treasury Secretary Steven Mnuchin said on Tuesday that licenses for the planemaker and rival Boeing Co to sell passenger jets to Iran would be revoked.

Le Maire said Paris was seeking U.S. waivers and longer transition periods over Iran for French companies including Renault and Total , while pressing for European Union measures to improve the bloc's "economic sovereignty" in the longer term.

"It's time that European countries opened their eyes," Le Maire said on Europe 1 radio.

French exports to Iran doubled to 1.5 billion euros ($1.79 billion) last year, driven by jets and aircraft and automobile parts, according to customs data.

Exports of German goods to Iran rose by around 400 million euros to 3 billion euros. Around 120 German firms have operations with their own staff in Iran, including Siemens , and some 10,000 German companies trade with Iran.

"We are ready to talk to all the companies concerned about what we can do to minimize the negative consequences," Altmaier told Deutschlandfunk radio. "That means, it is concretely about damage limitation".

But the U.S. ambassador in Berlin, Richard Grenell, said firms should question the morality of doing business with Iran.

"Germany, France and Britain, the 'EU3', say themselves that Iran poses a threat. Do they want to do business with a threat?" Grenell told Bild newspaper.

Altmaier said Germany wanted to avoid "a spiral of escalation" in transatlantic trade relations.

Merkel was more blunt.

"If everybody does what they like, then this is bad news for the world...," Merkel said during a church event in the western German city of Muenster.

"(But) it is in our interest to have a strong transatlantic relationship."

($1 = 0.8372 euros)

(Additional reporting by Joseph Nasr in Berlin and Laurence Frost in Paris; Writing and editing by Paul Carrel and John Stonestreet)