"I have said that no country in the world is enriching uranium at this level of 60%, which is technically almost equivalent of 90% which is needed to have a nuclear weapon. At the same time, we are inspectors, we are not political analysts or national political officials, so we have to have concrete proof in order to say that there is an active program to make a nuclear weapon, which we have not seen. That does not mean that they are in a territory which is of concern. And this is the reason why there is international concern," Grossi told Bloomberg.