European officials have reacted with dismay to this week’s US announcement that Iran halted its nuclear weapons programme in 2003, arguing that the findings give a misleading impression of the country’s progress towards the bomb and weaken international leverage on Tehran.

The Europeans’ disappointment is particularly acute because, until the report’s main conclusions were published this week, the US and European Union had appeared to be making headway in their goal of persuading Russia and China to sign up this month to a new wave of UN sanctions on Tehran. Iran says its programme is peaceful.