IAEA chief: 'In Iran, the Agency has neither received information on the status of declared nuclear material or facilities nor had access to conduct in-field verification activities during this reporting period. Our lack of information and inability to conduct verification is a serious proliferation concern that needs to be rectified with the utmost urgency. A return to diplomacy and negotiations is imperative: they are the only way to achieve long-term assurance that Iran will not acquire nuclear weapons'