Trump claimed that the deal, formally known as the Joint Comprehensive Plan of Action (JCPOA), had failed to prevent Iran from developing nuclear weapons or supporting terrorism in the region.
Mr Johnson said before the meeting: "We will be looking at all the ways we can come up with to protect legitimate United Kingdom and European businesses who may want to trade with Iran, who do want to trade and have great plans to do that".
Earlier this week, European Union foreign policy chief Federica Mogherini said that the foreign ministers of the UK, France, Germany, and Iran had agreed to work out practical solutions in response to Washington's move in the next few weeks.
"If Europeans stop trading with Iran and don't put pressure on U.S. then we will reveal which western politicians and how much money they had received during nuclear negotiations to make #IranDeal happen" Middle East analyst for The Jerusalem Post, Raman Ghavami tweeted the remarks allegedly made by Hassan Ghashghavi, the deputy foreign minister of Iran.
Heiko Maas, Germany's foreign minister, acknowledged that the process to resolve the issues surrounding the USA withdrawal would not be easy.
Referring to the US fresh sanctions against officials of Iran's central bank, Zarif said, "It's an illegal action, same as other actions of the United States".
"We reaffirm our resolve to continue to implement the nuclear deal in all its part, in good faith, and in a constructive atmosphere", said Mogherini.
The crux of the matter is that the yuan-denominated transactions are non-transparent for U.S. financial regulators, the economist pointed out, assuming that Chinese and European consumers could use Shanghai as a "black box" to evade United States sanctions while buying Iranian crude.
EU foreign-policy chief Federica Mogherini said on May 15 that European commissioners will first discuss whether the EU's 1990s-era sanctions-blocking measures can be used to protect European business interests in Iran before leaders at the summit take up the matter.
According to France 24 news agency, some European countries have been working out measures to bypass U.S. anti-Iranian sanctions since January 2018.
The EU wants to ensure exports to Iran, which have exploded since the deal was signed in 2013, can continue. Johnson said regime change in Iran was not a policy Britain should pursue.
Mohammad Javad Zarif, Iran's foreign minister, said collaboration with the European Union was on the right track. But senior Iranian official Ali Akbar Velayati said in Tehran that Iran's defensive missile programme was not negotiable. Supreme Leader Ayatollah Ali Khamenei, not Rouhani, has the last say on all state matters.
"We must expect more such moves by the Americans".
He said: "What we are going to do tomorrow in Brussels is we are going to have a conversation about what we can do to help United Kingdom firms, European firms have some confidence that they can still do business".