Japan has told the US it is ready to freeze bank accounts held by Iran and its leadership in support of an America-led coalition preparing sanctions in the event that Iran refuses to halt its nuclear fuel programme, officials have told the Financial Times.

Japan’s decision to join the “coalition of concerned countries” will be seen as a serious setback for Iran, which has tried to exploit divisions within the international community over how to respond to its alleged development of nuclear weapons. Iran provides more than 10 per cent of Japan’s oil imports.