Iran has dramatically increased its stockpile of uranium needed to create nuclear weapons and has fallen short of compliance with international regulators, according to an IAEA report.

The U.N. nuclear watchdog says Iran has further increased its stockpile of uranium enriched to near weapons-grade levels.

U.N. inspectors monitoring Iran's Fordow nuclear site confronted a major gap in their knowledge last year as they watched trucks carrying advanced uranium-enriching centrifuges roll into the facility dug into a mountain south of Tehran.