The IAEA, the UN's nuclear agency, said in today's report that Iran has even increased its installation of centrifuges, which enrich uranium, at its Natanz facility.
The UN nuclear watchdog said that increase represents an effort to expand, rather than freeze, sensitive nuclear work as demanded by the UN.
The IAEA report has been sent both to the agency's board of governors, which has 35-member countries, and to the UN Security Council.
Iran's refusal to observe the UN deadline exposes the country to broader UN sanctions. The Security Council adopted a resolution in December imposing limited sanctions aimed at curbing Iran's nuclear program. It gave Iran 60 days to halt uranium enrichment or face additional measures.
The deadline expired on February 21 and Iranian officials said the country will continue its nuclear work.
The U.S. State Department said Iran's refusal to comply with the Security Council demands was "a missed opportunity for the Iranian government and the Iranian people."
State Department spokesman Tom Casey says the U.S. position is that the Security Council should respond with additional steps beyond the limited sanctions it approved in December.
French Foreign Minister Philippe Douste-Blazy told reporters shortly after the release of the IAEA report that his country wants a second resolution to be adopted by the Security Council to continue sanctions.
The IAEA report says Iran has expanded from research-scale to industrial-scale production of enriched uranium. It says two cascades of 164 centrifuges each had been installed at the enrichment facility in Natanz, with two more close to completion.
The report says Iranian officials Iran have told the IAEA that they wanted to install up to 3,000 centrifuges and bring them into operation by May.
The IAEA also says there had been little progress in clearing up outstanding questions about Iran's past nuclear activities.
Yet an Iranian official said the report shows Iran's peaceful intentions.
The deputy head of Iran's Atomic Energy Organization, Mohammad Saidi, told Reuters that the report shows that the best way to resolve the issue is to return to the negotiating table and reach a broad agreement.
Iran says its nuclear activities are entirely peaceful. But Western countries suspect Iran is covertly seeking to produce nuclear weapons.
U.S. Secretary of State Condoleezza Rice said today that world powers plan to use all available channels, including the UN Security Council, to get Iran to halt its nuclear enrichment work and start negotiations.
(compiled from agency reports)