Sofia - Leaders of the European Union were united in their resolve that the Iran nuclear deal needed to be preserved despite the US decision to withdraw from it, they said on Thursday.

The bloc's leaders discussed the issue during a working dinner Wednesday night in the Bulgarian capital, one week after President Donald Trump's decision to pull out of the 2015 agreement meant to prevent Iran from acquiring nuclear weapons in return for the lifting of sanctions.

Trump's decision to leave the deal means sanctions could be reimposed on Iran, as well as European companies doing business there.

"Everyone in the European Union shares the view that this agreement is not perfect, but that we should remain in this agreement and continue to conduct further negotiations with Iran on other issues, such as the ballistic programme," German Chancellor Angela Merkel said.

Maintain the nuclear agreement with Iran

French President Emmanuel Macron said, "We are going to work to uphold the framework of the 2105 agreement, whatever American decisions are taken." He noted that leaders showed "real" unity "to protect Europe’s strategic and economic sovereignty."

Macron said he was working towards a broader agreement that would complement the 2015 deal with an agreement on Iran's nuclear programme after 2025, when the original deal's provisions expire.

Additional agreements should also be reached regarding Iran's ballistic missile programme and its regional aspirations.

Austrian Chancellor Sebastian Kurz said it was important that EU countries react in a coordinated manner, which was visible during the working dinner. "We all pull together here," Kurz said.

Security of Europe

He noted that the agreement was good for Europe's security because it makes sure that Iran cannot acquire nuclear weapons.

"We have a few weeks left to save it," he said. "No one can tell right now if that will work, but we'll do our best."

Trump says the deal is "defective at its core" because it was poorly negotiated and does not do enough to check Iran's regional ambitions and missile programme.