The U.N. atomic watchdog sat down to discuss the Iran nuclear dossier, the last major topic on the agenda of its regular March board meeting here, which could be wrapped up by end Wednesday.
After already discussing a range of issues over the past two days, including the stalled disarmament process in North Korea, at least 16 speakers were to address the International Atomic Energy Agency's 35-member board of governors on the third day of debate.
With discussion expected to last at least until midday or the early afternoon, the board meeting could be wrapped up by Wednesday evening or early Thursday.
A push by Western nations Tuesday for a resolution against Iran was dropped amid objections from Russia, China and developing countries.
Just a day after the U.N. Security Council slapped a third set of sanctions on Iran over its refusal to suspend uranium enrichment, European countries drafted a resolution which they wanted to put to the IAEA board.
But the text was finally ditched after its opponents - notably the Russians and the Chinese - argued it was superfluous following the U.N. Security Council decision.
The idea of a separate IAEA resolution had been to turn up the pressure on Iran to clear up allegations of alleged nuclear weapons work.
Western diplomats felt recent intelligence suggesting Tehran is involved in nuclear weapons work would have sufficiently raised concern within the IAEA to ensure the passage of such a resolution at the agency's board meeting.
Last week, the IAEA board was shown intelligence from a number of independent sources that suggested Tehran was involved in a uranium conversion project, high explosives tests and a missile reentry vehicle modified to accommodate what could be a nuclear warhead.
The information also suggested Iran continued nuclear weapons work beyond the 2003 date cited in a recent U.S. intelligence report.
Iranian Ambassador Ali Asghar Soltanieh Tuesday held a power point presentation of his own as a counteroffensive against the allegations.
However, the IAEA has complained that simple denials on Tehran's part are not enough and that a "full-fledged examination" of the matter was necessary to determine the full scope and nature of Tehran's nuclear drive.
The U.N. resolution in New York gives Iran three months to comply with U.N. and IAEA demands to suspend uranium enrichment and reprocessing to help restore international confidence in the peaceful nature of its nuclear program or face new sanctions.
It includes an outright ban on travel by officials involved in Tehran's nuclear and missile programs, and broadens a list of individuals and entities subject to an assets freeze.
Western countries say Iran's uranium enrichment activities are aimed at developing nuclear weapons, while Tehran insists it is only interested in energy production.