VIENNA (AP) — Top diplomats from Iran and five world powers sat down in Vienna on Friday to hash out what steps are needed to preserve the nuclear deal with Tehran following the withdrawal of the United States.

The meeting Friday between Iran, Germany, Britain, France, Russia and China will consider proposals for salvaging the 2015 deal, known as the Joint Comprehensive Plan of Action, which is meant to prevent Tehran from developing nuclear weapons.

Arriving in Vienna, Chinese Foreign Minister Wang Yi said preserving the deal was critical, and that the treaty states would send a “united, determined and strong signal” that they were committed to it despite U.S. President Donald Trump’s decision in May to pull out American support.

“If this treaty can’t be upheld then this doesn’t just hurt the interests of Iran, it also damages the peace in the Middle East and the credibility of the international world order,” Wang said.

Trump said he was unilaterally pulling out of the deal negotiated by his predecessor because he felt it wasn’t strong enough and didn’t cover other issues of concern to the U.S. and its allies, such as Iran’s military influence in the Middle East and a ballistic missile program.

Iran’s economy is already suffering from the sanctions that Washington re-imposed after walking away from the nuclear agreement, and the U.S. has threatened to punish companies from other nations that continue doing business with Iran.

Heading in to the talks, German Foreign Minister Heiko Maas conceded that the treaty nations would not be able to compensate Iran entirely for the loss of business from companies withdrawing, but said they would advise firms that want to continue investing and emphasize to Iran that leaving the deal “would have much greater disadvantages.”

“We want to make it clear to Iran today that it still has economic benefits from this agreement,” Maas told reporters. “Above all we will try to create the conditions for that.”

Maas said he expected negotiations to continue after the Friday talks, which were convened at Iran’s request.

“We are formulating an offer which, in our opinion, is also attractive for Iran,” Maas said. “We want this agreement to be maintained in the future.”

In calls Thursday with German Chancellor Angela Merkel and French President Emmanuel Macron, Iranian President Hassan Rouhani said since the U.S. withdrawal “Iran has been dealing with economic issues and problems in banking relations and oil” and that foreign companies were “skeptical” about continuing their business, Iran’s semi-official Mehr news agency reported.

He said that up to now, the package of incentives proposed to Iran were “disappointing,” and that they “lacked an operational solution and a specific method for cooperation, and featured just a set of general commitments.”

Rouhani expressed hope, however, that the diplomats would be able to make progress.

“If the process of the European foreign ministers’ meeting in Vienna, which is aimed at encouraging Iran to cooperate, is promising, we will continue our cooperation,” he said.

_____

David Rising and Frank Jordans in Berlin contributed to this story.