Iran's foreign minister said today that efforts to save the nuclear deal after the abrupt US withdrawal were "on the right track" as he began talks with European powers in Brussels. Mohammad Javad Zarif met EU foreign policy chief Federica Mogherini ahead of evening talks with his counterparts from Britain, France and Germany - the three European signatories to the 2015 landmark accord who are scrambling to preserve it. Tehran has warned it is prepared to resume "industrial-scale" uranium enrichment "without any restrictions" unless Europe can provide solid guarantees that it can maintain the economic benefits it gained from the nuclear agreement despite the United States reimposing sanctions. Zarif gave an upbeat assessment after a "good and constructive" meeting with Mogherini. "I believe we're on the right track to move forward in order to ensure that interests of all the JCPOA remaining participants, particularly Iran, will be preserved and guaranteed," he told reporters. The deal's official name is the Joint Comprehensive Plan of Action, or JCPOA. Mogherini said it had been a "very productive" meeting but indicated it was the start of a long road. "We are working on the measures that we can start to put in place and we will look at the content of that," she said. "One thing is absolutely sure is that the European Union is determined to preserve this deal that is essential to our security and the security of the region." Zarif's meetings in Brussels cap a whirlwind global tour, including trips to both Russia and China, the two other signatory nations, in a bid to bolster support. Europeans have sought to play down expectations of Tuesday's meeting, stressing the enormous challenge of finding a way around US sanctions punishing foreign businesses trading with Iran, which have global reach. The European Union insists the deal is working, pointing to repeated UN inspections verifying the Islamic republic's compliance with its side of the bargain. We will make it clear to Zarif "that we stand by the agreements and also expect Iran to abide by them," said German Foreign Minister Heiko Maas. EU leaders aim to show a united front on preserving the Iran deal when they meet for a pre-summit dinner in Sofia on Wednesday, European Council President Donald Tusk said. "I would like our debate to reconfirm without any doubt that as long as Iran respects the provisions of the deal, the EU will also respect it," Tusk said in a letter to the leaders on the eve of the summit. European firms, especially those from France and Germany, rushed to invest in Iran following the 2015 accord, under which Tehran agreed to freeze its nuclear programme in return for an end to punishing international sanctions. German exports to Iran totalled nearly 3.0 billion euros in 2017, while French exports soared from 562 million euros in 2015 to 1.5 billion in 2017 and oil giant Total has pledged to invest some $5 billion in the South Pars gas field. When he quit the deal last week, US President Donald Trump gave businesses a maximum of six months to wind up operations in Iran or face swingeing penalties under American sanctions. "We have to be realistic about the electrified rail, the live wire of American extra-territoriality and how that can serve as a deterrent to business," said British Foreign Secretary Boris Johnson. French President Emmanuel Macron held phone talks with his Russian counterpart Vladimir Putin on Tuesday, according to a Kremlin statement, which said they had "confirmed Russia and France's commitment to make the deal work". Zarif was in Moscow to meet Russian Foreign Minister Sergei Lavrov on Monday, a day after visiting Beijing. Johnson said the Europeans were "under no illusion about Iran's disruptive behaviour but we think we can tackle those in other ways outside the JCPOA." Washington has long complained that the nuclear deal does nothing to stop Iran's ballistic missile programme or its interference in conflicts across the Middle East from Syria to Yemen.