An early November report from the International Atomic Energy Agency stated that nuclear inspectors were unable to conclude that all of the nuclear material in Iran was intended to be used for peaceful purposes.
Iran is suspected of pursuing the technology needed to manufacture a nuclear weapon. The government there denies the allegation.
IAEA Director General Yukiya Amano briefed the agency's Board of Governors Thursday in Vienna on the "intensive efforts" under way to resolve Iranian nuclear issues. He said he was concerned that Iran might be hiding nuclear activity from inspectors at its Parchin military complex outside Tehran.
He said that the IAEA was able to verify that Iran's nuclear material wasn't diverted for other than peaceful means.
"However, Iran is not providing the necessary cooperation to enable us to provide credible assurance about the absence of undeclared nuclear material and activities, and therefore to conclude that all nuclear material in Iran is in peaceful activities," he said.
Iran's state-funded broadcaster Press TV reports that nuclear officials confirmed that "four or five" batches of fuel material were delivered to a nuclear research reactor in Tehran this week.