In a BBC interview, the former head of the International Atomic Energy Agency (IAEA), Mohamed ElBaradei, said Western nations were seeking harsher sanctions "out of frustration". "I don't think Iran is developing, or we have new information that Iran is developing, a nuclear weapon today," he said. "There is a concern about Iran's future intentions, but even if you talk to MI6 or the CIA, they will tell you they are still four or five years away from a weapon. So, we have time to engage." He said it was a "question of building trust between Iran and the US". "That will not happen until the two sides sit around the negotiating table and address their grievances. Sooner or later that will happen."