VIENNA, Austria - In comments suggesting exasperation, the head of the U.N. atomic watchdog agency urged Iran today to replace foot-dragging with "full cooperation" with his agency's probe of suspicious nuclear activities.

Mohamed ElBaradei, director-general of the International Atomic Energy Agency, spoke outside a meeting of the IAEA's 35-nation board of governors, which was reviewing Iran's record of working with the agency.

An Iran resolution will likely be presented during the meeting, which began today. The gathering will review an agency report that notes Iran's cooperation in granting IAEA inspectors access to sites but otherwise gives it low marks in eliminating concerns that its nuclear program aims to produce nuclear weapons, as the United States believes.

The two major IAEA concerns are contradictory, missing or withheld information on the scope of Iran's enrichment program and the source of enriched uranium found inside the country.

"These are two issues where we need accelerated and proactive cooperation on the part of Iran," ElBaradei told reporters just before the meeting opened. "The way they have been engaging us on these issues has been less than satisfactory."

Diplomats close to the agency characterized his remarks as blunt and suggested they expressed clear impatience with lack of progress a year into the probe of nearly two decades of covert nuclear programs.

In separate comments inside the meeting, ElBaradei said Iran's responses to IAEA requests about its centrifuge enrichment program have been "changing and at times contradictory."

While the Iran resolution will not directly threaten sanctions, a toughly worded document would maintain pressure on Iran to come clean.

Iran has denied being uncooperative and has rejected U.S. allegations that its nuclear program is for military purposes. It says its uranium-enrichment program is geared solely toward generating electricity.

Under pressure, Iran has already suspended uranium enrichment and stopped building centrifuges. It has also allowed IAEA inspections of its nuclear facilities without notice.

ElBaradei said last month the IAEA had so far not found proof of a concrete link between Iran's nuclear activities and its military program, but "it was premature to make a judgment."