Iran's foreign minister says Tehran and European powers have made a "good start" in talks over how to salvage the 2015 nuclear deal in the wake of Washington's withdrawal.
Mohammed Javad Zarif made the comments in Brussels late on May 15 following talks with his counterparts from Britain, France, and Germany.
"We are on the right track...a lot will depend on what we can do in next few weeks," Zarif said after the 90-minute meeting.
EU foreign-policy chief Federica Mogherini, who also attended the meeting, said the four ministers shared a willingness to find "practical solutions" for keeping the nuclear accord going.
She said there was "awareness of the urgency" and the ministers agreed to find some solutions within weeks.
The EU cannot provide legal and economic guarantees to Tehran but is serious about seeking a way to keep investment flowing, the bloc's top diplomat also said.
The Iranian minister was in Brussels on the final stop of a global tour aimed at rallying support for the landmark nuclear accord between Tehran and six world powers.
In addition to the United States and Iran, the agreement known as the Joint Comprehensive Plan of Action (JCPOA) was signed by Russia, China, Britain, France, Germany, and the European Union.
U.S. President Donald Trump pulled out on May 8, claiming that Iran had violated the "spirit" of the deal by financing militant violence in the Middle East and by continuing to test ballistic missiles.
The EU hopes to convince Tehran to continue to adhere to the accord.
British Foreign Secretary Boris Johnson said before the meeting with Zarif that Britain and its European partners "continue to view the nuclear deal as vital for our shared security, and remain fully committed to upholding it."
"We want to hear what expectations there are in Iran," German Foreign Minister Heiko Maas said. "We will look for ways in which we can make sure that in Iran the deal can still be supported from a domestic political perspective."
In Berlin, German Chancellor Angela Merkel acknowledged that the nuclear deal "certainly has weaknesses," but said that sticking to it was the best way forward.
Speaking at a labor union congress, Merkel said that Europe wasn't "blind" to threats posed by Tehran's activities in countries such as Syria to Israel.
"But we still think that, with the agreement, we would have better preconditions to speak with Iran about further agreements than by unilaterally canceling an agreement that was unanimously approved and endorsed in the UN Security Council," she added.
Earlier on May 15, Russian President Vladimir Putin discussed the Iran deal with French President Emmanuel Macron by phone, the Kremlin said.
The two leaders reiterated their commitment to the Iran accord in the phone call, the Kremlin press service said in a statement.
Meanwhile, the head of Iran's Atomic Energy Organization called on the European signatories to make up for the U.S. withdrawal from the nuclear agreement.
"If they cannot do that, we are ready to take our nuclear program to a level stronger than before the JCPOA," Ali Akbar Salehi warned in an interview on state television.
Zarif arrived in Brussels from Russia, where he and Foreign Minister Sergei Lavrov on May 14 agreed to remain in "close contact" over the deal.
Lavrov told Zarif that all the remaining signatories of the JCPOA have "legitimate interests" in keeping the deal and that "therefore we need to defend the legitimate interests of each of us together." Zarif said that Russia had confirmed its readiness to respect the pact.
Russian acting Deputy Foreign Minister Sergei Ryabkov said on May 15 it was possible to discuss the future of the Iran nuclear deal without the participation of the United States, the RIA Novosti news agency reported.
Ryabkov, speaking at a meeting in Moscow of the Valdai Discussion Club -- a gathering of Russian and international foreign-policy experts -- also said there had been an attempt to present the situation in a way that it would be impossible to preserve the deal without Tehran making concessions, the Interfax news agency reported.
After his talks in Beijing on March 13, Zarif said Iran wanted a "clear future design" for the accord, adding that "the interests of the people of Iran must be assured."