France says the US has rejected its request to exempt French companies from sanctions that Washington plans to impose against Iran.

French Finance Minister Bruno Le Maire was quoted by media as saying that the US Treasury Department had officially informed Paris that no exemptions would be given to French enterprises for dealing with Iran once the sanctions return.

"We have just received Treasury Secretary Steve Mnuchin's response: it's negative," Le Maire told Le Figaro in an interview published on Friday.

The French minister said 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 said.

Foreign and finance ministers of France, Germany and Britain wrote a letter to senior US officials last month, singling out key areas which they wanted to be excluded from US sanctions.

In their letter, the European ministers wanted key areas, including pharmaceuticals, healthcare, energy, automotive, civil aviation, infrastructure and banking to be exempted.

The ministers have said US measures, including its secondary sanctions that could prevent the European Union from continuing to uphold the 2015 nuclear agreement with Iran, would harm Europe’s security interests.

Earlier in June, Le Maire said that Europe had to build independent financial institutions that would be immune to US penalties which he said are already making it impossible for European companies to do business with Iran.

Some major French firms such as energy giant Total and carmaker PSA have already been winding down their activities in Iran, but Renault has said that it will stand its ground.

The European Union is currently locked in a trade dispute with the US.

In May, US President Donald Trump announced that he would pull America out of the nuclear agreement with Iran and re-impose the sanctions that the deal had envisaged to be lifted.

Trump emphasized that the sanctions against Iran would be “at the highest level.”

The first batch of sanctions that will come into force in August will target the Central Bank of Iran (CBI) as well as the country’s precious metals sector. The next batch that will be implemented in November will target Iran’s oil and energy sector.

Iran has strongly criticized Trump's decision to pull America out of the nuclear deal - the Joint Comprehensive Plan of Action (JCPOA) as it is technically called. It says the move is a clear violation of the JCPOA, emphasizing that other signatories should provide assurances that Iran continues to benefit from the economic advantages envisaged in the deal.

Europe has pledged to put together an economic package for Iran so that the country benefits from staying in the deal but France said on July 6 the offer was unlikely to come by before November.

Germany's Foreign Minister Heiko Maas has also said that the Europeans would not be able to fully compensate for companies leaving Iran due to the returning US sanctions.