Britain said on Wednesday that U.S. sanctions against Iran were having a clear impact on other countries and were making it difficult for firms to assess the risks of doing business there.
U.S. President Donald Trump on 8 May withdrew from a deal between Iran and major world powers whereby some sanctions against Tehran were lifted in exchange for curbs on its nuclear programme. Trump has since imposed new sanctions, cutting Iran's use of a critical banking network.
"It is clear that there is extra-territorial reach to some of these sanctions," said Rona Fairhead, a trade department minister in the upper house of the British parliament, acknowledging that the sanctions would have an impact on trade between Iran and countries other than the United States.
"All businesses have to take into account the commercial risks, the legal risks, the financing risks of any transaction, and clearly these sanctions make that difficult," she said.
Fairhead said Britain was providing guidance on the ground in Iran and at home to help companies navigate those risks and was also working with other governments to keep trade ties alive.
"We are working with our EU colleagues and directly both with the U.S. and with the EU to try and both protect our businesses as well as encourage the U.S. to allow us to continue economic ties because we think that's important," she said.
British, French and German foreign ministers met in Brussels on Tuesday to see how they can save the nuclear deal without the United States, but appeared hard-pressed over how their companies could continue doing business with Iran once Washington begins to reimpose sanctions.