Britain continues to believe that the Iran nuclear deal “has value” despite the US walking away from it, Boris Johnson said as he arrived in Brussels for talks with his French and German counterparts.

The talks in Brussels on Tuesday evening will be followed by a meeting with the Iranian foreign minister Mohammad Javad Zarif in an intensive diplomatic effort to shore up agreement over the Joint Comprehensive Plan of Action (JCPOA) agreed in 2015.

Britain, France and Germany are working to secure measures to protect European countries working in Iran against the danger of US sanctions after President Donald Trump withdrew from the deal.

Iranian foreign minister Mohammad Javad Zarif
Boris Johnson will meet with Iranian foreign minister Mohammad Javad Zarif (Jonathan Brady/PA)

Arriving in the Belgian capital, Mr Johnson said: “We think it (the JCPOA) has value, we continue to believe in it even though America has decided to walk away.

“So we will be looking at a package of measures that we may be able to devise as Europeans to encourage the Iranians to stay in the deal.

“We are under no illusions about the stuff Iran gets up to in the region, in the Middle East.

“We have no illusions about Iran’s disruptive behaviour, but we think we can tackle those in other ways outside the JCPOA.”

Mr Johnson held talks with French foreign minister Jean-Yves le Drian in London on Monday and said Britain stands shoulder to shoulder with Paris on the need to preserve the JCPOA, which removed sanctions on Iran in return for Tehran giving up its military nuclear programme.

The pair will be joined by German foreign minister Heiko Maas in Brussels at a meeting hosted by the European Union’s foreign policy chief Federica Mogherini.

The meeting comes amid fears that European companies may face reprisals from the US for breaching American sanctions by continuing to operate in Iran.

Mr Johnson added: “We will be looking at all the ways we can come up with to protect legitimate UK and European businesses who may want to trade with Iran, who do want to trade and have great plans to do that.

“But we have to accept, 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 … that doesn’t mean there aren’t some things we can do.”