The visit, which has been planned for some time, will be seen in Tehran as the next stage in a mutual effort to improve relations with the UK since sanctions were lifted against Iran when the international nuclear deal was signed in January 2016.

"A number of European countries are ahead of the UK in relations with Iran since the nuclear deal, including in economic relations," an Iranian official source, who declined to be named, said.

Tehran has expressed frustration that British banks have been reluctant to facilitate trade with the country since sanctions were lifted following the signing of the nuclear deal in January 2016.

Some western banks, including in London, are understood to be wary of falling foul of separate sanctions the United States kept in place despite lifting nuclear-related measures in 2016.

Talks will also touch on disagreements over regional issues such as Syria and Yemen.

The visit comes amid heightened tensions in the Middle East following Donald Trump's decision to recognize Jerusalem as the capital of Israel and move the US embassy there.

Mr Johnson sought to distance Britain from Mr Trump's decision on Thursday, calling the move "unhelpful."

"We ... think that the future of Jerusalem must be settled as part of the negotiated agreement between Israel and the Palestinians and as part of the two-state solution," he said.