By LORNE COOK and ANGELA CHARLTON
BRUSSELS (AP) - European powers involved in the Iran nuclear agreement expressed regret Tuesday at President Donald Trump's decision to pull the U.S. out of the landmark pact amid concern the move will undermine efforts to stop the spread of atomic weapons.
After Trump's announcement, French President Emmanuel Macron spoke with German Chancellor Angela Merkel and British Prime Minister Theresa May - leaders of the three European Union countries that negotiated the 2015 deal with the U.S., Russia, China and Iran.
"It is with regret and concern that we, the Leaders of France, Germany and the United Kingdom take note of President Trump's decision to withdraw," they said in a joint statement. "Together, we emphasize our continuing commitment to the (deal). This agreement remains important for our shared security."
"The world is a safer place as a result" of the agreement, they said, and vowed to continue to uphold it with their partners.
European Union foreign policy chief Federica Mogherini, who helps supervise the way Iran and major world powers implement the deal and settle any disputes, expressed concern about Trump's suggestion that new sanctions might be slapped on Iran.
"I am particularly worried by the announcement tonight of new sanctions," Mogherini told reporters in Rome, adding that she would consult with Europe's partners about any new measures "to assess their implications."
"In any case, the European Union is determined to act in accordance with its security interests and to protect its economic investments," she added.
In a message directed to Iran itself, Mogherini said: "Do not let anyone dismantle this agreement. It is one of the biggest achievements diplomacy has ever delivered, and we have built this together."
The precise impact of Trump's decision will probably take some time to decipher. The agreement is endorsed by the U.N. Security Council and can't be ended by any one party alone.
In the short term, U.S. Congress now has about 60 days to decide its next move. Iran can also trigger a dispute mechanism in the agreement, opening a maximum 45-day window for the airing of grievances and to seek a compromise. This could buy three months of valuable time.
Overall, Trump's threats have baffled the Europeans. They say the deal is working and note that the International Atomic Energy Agency has now certified 10 times that Iran is in compliance with its obligations.
They wonder how breaking this deal would improve things and fear it might only create a dangerous vacuum for Iran to resume its nuclear activities.
"If this agreement falls apart and you don't have a substitute, what do you gain? You make things worse because you probably trigger a nuclear arms race in the region," a senior EU official with close working knowledge of the agreement said Thursday. The official wasn't permitted to speak publicly about the Iran nuclear dossier.
The deal "is not based on assumptions of good faith or trust. It is based on concrete commitments, verification mechanisms and a very strict long-term monitoring done by the IAEA," the official said.
EU officials also warn that any changes Trump might want to make to this agreement would have to be done on the basis of "more for more." They believe Iran is unlikely to accept new constraints without concessions in return.
That said, it is still possible to ramp up pressure on Iran over its ballistic missile program or its destabilizing role in regional affairs through other sanctions, which would fall outside the scope of the agreement.
Just in case U.S. sanctions linked to this agreement do kick in, the EU is weighing how to protect the interests of European businesses working with Iran.
"We are having conversations obviously and we are working on a number of proposals that could protect European companies and operators," the senior official said, but declined to provide details.
Angela Charlton reported from Paris.