The deal’s implementation is pending approval from the US Congress and the Iranian Majles (parliament), as well as the implementation by Iran of nuclear-related measures described in the deal. “UKEF has outstanding claims on Iran and we would expect these arrears to be regularised to a large degree before we would be in a position to restore full cover”, it added.

“By signing this deal, Britain is not aligning with Iran“, Cameron said in an interview with news channel Al Arabiya on Friday, according to a transcript released by his Downing Street office.

Iran has for years rejected IAEA requests to visit the site and denies ever having worked on developing a nuclear weapon, saying Parchin is a non-nuclear facility.

However, the largest bank in Germany by assets Deutsche Bank announced it would consider doing some business in Iran only after the sanctions have disappeared. The gradual and partial removal of sanctions could help Iran’s domestic demand rebound rapidly, especially if oil exports normalise to pre-2012 levels.

Moreover, although Iran has around 20 million barrels of oil in storage, some of it is needed for operational reasons domestically and is therefore, not destined for export, the report said.

The IIF observed that lifting the sanctions would spur a sharp economic recovery with a rise in oil exports, regained access to frozen foreign assets (estimated at about $100 billion), and sizeable foreign capital inflows, largely in the form of foreign direct investment.

“The money is sitting in China, India, Japan, South Korea, Turkey, maybe a little bit in Taiwan”, says Mark Dubowitz, the executive director of the Foundation for Defense of Democracies.

“No company wants to wake up to a front-page story that its business partner is Iran’s Islamic Revolutionary Guard Corps or that the new US president has re-imposed tough sanctions”, Dubowitz said.

His ministry said there was “great interest on the part of German industry in normalising and strengthening economic relations with Iran”.

Business in Iran will also be complicated by an outdated legal system, restrictive labor laws and a lack of experience in dealing with global investors, said Firas Abi Ali, head of Middle East analysis at IHS Cambridge Energy Research.

“Although the deal will present foreign oil and gas companies in particular with a broad range of opportunities, the operating environment in a post-sanctions Iran will nearly certainly remain challenging”, said Torbjorn Soltvedt, an analyst with Verisk Maplecroft. In a first step to begin normalization of trade between Tehran and Britain, the export credit agency in the United Kingdom it was planning to review the creditworthiness of Iran. “Banks are highly risk-averse and will remain hesitant” for a long period of time, he said.

Iran, which has the world’s fourth-biggest oil reserves, has seen its production fall to less than three million barrels per day (bpd) since 2012.