The US has turned down high-level pleas from the EU to award waivers to European companies that would shield them from sanctions against Iran and protect billions of dollars’ worth of trade and investment.

News of the rebuff emerged in an interview given by French Finance Minister Bruno Le Maire to Le Figaro on July 13.

“We have just received Treasury Secretary Steve Mnuchin’s response [to the request for French companies]: it’s negative,” Le Maire told the newspaper in an interview. He said that Europe needed to react quickly and protect its economic sovereignty. “Europe must provide itself with the tools it needs to defend itself against extra-territorial sanctions,” he reportedly added.

France sought the waivers after US President Donald Trump withdrew from the Iran nuclear deal in early May and announced the reimposition of heavy sanctions against the Islamic Republic. In a letter to European nations explaining the decision not to grant the waivers, US Secretary of State Mike Pompeo said Washington rejected the appeal because it wants to exert maximum pressure on Iran.

Paris, which remains in the nuclear accord along with all the other signatories except the US, wants exemptions or extended wind-down periods for French companies in four key areas including energy, banking, pharmaceuticals and automotive. But French officials have never shown much hope that the Trump administration, attempting to throttle Iran’s economy to the point where the Iranians would come to the table to negotiate a tougher nuclear deal, would grant the waivers.

"We will seek to provide unprecedented financial pressure on the Iranian regime," the letter from Pompeo, also signed by Mnuchin, said, according to NBC news. It added that the US is "not in a position to make exceptions to this policy except in very specific circumstances", such as to benefit US national security.

Energy major Total and carmaker PSA Group, which assembles Peugeot and Citroen models in joint ventures with Iranian partners, had already signalled they are set to depart Iran, fearing they would otherwise be hit by secondary sanctions levied by Washington.

Meanwhile, July 13 also saw French reinsurer Scor saying it would not pursue new contracts or renew existing business in Iran, given impending US sanctions.

All eyes are now on how aggressive Trump will be in attempting to halt virtually all buying of Iran’s oil exports by November. Oil revenues are indispensable to Iran’s economy and Iranian President Hassan Rouhani earlier this month appeared to threaten to disrupt oil shipments from its neighbours if Washington moved ahead with its plan to try to force countries to stop buying Iranian crude.

In 2017, EU exports to Iran in goods and services totalled €10.8bn, while imports from Iran to the bloc were worth €10.1bn, IMF figures show. The value of imports was nearly double the 2016 figure. The most valuable destination for Iranian exports was China at towards €16bn. Third was India at just over €8bn, fourth was South Korea at a little more than €6bn and fourth was Turkey, also at slightly more than €6bn.

Earlier this year, the EU began a process to reintroduce legislation that it says will allow its companies to continue doing business with Iran. The "blocking statute" was introduced in 1996 to circumvent US sanctions on Cuba but was never used. An updated version of the measure should be in force before 6 August, when the first of the fresh US sanctions directed at Iran kick in.