With US President Donald Trump threatening to impose more sanctions, Iran remains frozen out of much the international financial system despite the 2015 nuclear weapons deal.

Ed Butler speaks to a British businessman who has plenty of would-be Iranian buyers of his oil equipment, but who cannot get paid into his UK bank account. Sanctions lawyer Nigel Kushner explains why most international banks still steer clear of Iran, despite the lifting of sanctions, plus Ellie Geranmayeh of think-tank the European Council on Foreign Relations explains the latest diplomatic rumblings.

(Picture: Iranian rial banknotes, alongside US one dollar bills; Credit: Atta Kenare/AFP/Getty Images)