The International Atomic Energy Agency says that after two-and-a-half years of intensive inspections and investigation, it cannot say there are no undeclared nuclear materials or activities in Iran. In a confidential report leaked to Western news agencies Friday, the U.N. nuclear watchdog said Iranian transparency is long overdue. The report says Iran has pumped about seven tons of the gas it needs for uranium enrichment, which -- according to nuclear experts -- is enough for a nuclear bomb. But the report also confirmed recent revelations that traces of weapons-grade uranium found in Iran had most likely been imported on equipment purchased on Pakistan's black market. Iranian chief nuclear negotiator Ali Larijani said that although the report contained some negative points, Tehran would continue to cooperate with the IAEA.