British Foreign Secretary Elizabeth Truss has told Iran she hopes the UK will soon be able to repay its £400m debt to Tehran. Truss and to her Iranian counterpart, Hossein Amir-Abdollahian, spoke on Monday in a telephone conversation that appeared warmer than expected, an Iranian source was cited by The Guardian as saying. The debt stems from a cancelled 1970’s weapons agreement, in which Iran paid for paid for tanks that were never delivered. The money is believed to be a key sticking point for Iran in discussions relating to the release of British-Iranian nationals it has jailed.During the c…