International Atomic Energy Agency chief Yukiya Amano has said that Iran has not been forthcoming about its nuclear program and may have failed to declare some facilities to the UN. "Iran is not telling us everything. That is my impression. We are asking Iran to engage with us proactively, and Iran has a case to answer," Amano told CNN in an interview. Amano said that the IAEA has safeguarded a number of Iranian nuclear facilities, which the Islamic Republic has declared to the agency. "For these facilities and activities, I can tell that they are in peaceful purpose. But there are also, there may be other facilities which are not declared, and we have the indication or information that Iran has engaged in activities relevant to the development of nuclear explosive devices," he said.