UN nuclear watchdog head Mohamed ElBaradei has dismissed claims he timed news of missing explosives in Iraq to affect the outcome of the US election.
ElBaradei says a letter from Iraqi authorities sparked the revelations
The accusations, made by some American commentators, were "total junk", Mr ElBaradei told the Associated Press.
He said he told the US government about the missing explosives in confidence, but that the New York Times newspaper found out and published the story.
The issue has become a major theme in the US presidential election campaign.
"It's total junk," the head of the International Atomic Energy Agency (IAEA) told AP, when asked about the accusations.
"The timing probably is unfortunate, but there is a world out there other than the American election," he said.
Mr ElBaradei said the timing "was driven" by a letter from Iraq's Ministry of Science and Technology to the IAEA.
The letter said nearly 350 metric tons of high explosives had disappeared from the al-Qaqaa military site after 9 April 2003 - the day Baghdad fell to the US-led forces - as a result of "theft and looting... due to lack of security".
"I informed the US government with the hope that before the issue broke in public that they can retrieve it," Mr ElBaradei told AP.
"But once it became public, of course, I had to inform the Security Council immediately."
The Wall Street Journal called it "the UN's revenge".
"The United Nations appears to have cast its vote in the US presidential election this week.. It used 377 [US] tons of high-grade Iraqi explosives to announce its opposition to re-electing George W Bush," the newspaper wrote in an editorial.
The BBC's Pentagon correspondent, Nick Childs, says the issue has turned into a political emblem for both sides in the US election, just a few days away from polling day.
Democratic challenger John Kerry has accused President Bush of incompetence for not ensuring that US forces secured the material.
Mr Bush, for his part, has hit back at what he called "wild charges" made by Mr Kerry for political reasons.
The issue took a new twist on Friday when a US television station showed footage, shot by a crew embedded with the 101st Airborne Division, of troops inspecting explosives at al-Qaqaa on 18 April 2003.
ABC News said experts who had studied the video believed barrels seen in the video contained the high explosive HMX, with UN markings on the sealed containers.
David Albright, a former UN weapons inspector, told ABC the footage appeared to tally with what colleagues had seen at the site and that an IAEA seal was visible.
The Pentagon later held a news conference, at which Maj Austin Pearson said his team removed and later destroyed 250 metric tons of material including TNT and plastic explosives on 13 April 2003.
However, neither he nor Pentagon spokesman Larry DiRita could confirm that the material was part of the weapons cache sealed by the IAEA.
Maj Pearson told reporters: "I did not see any IAEA seals at locations we were looking into."
The IAEA last inspected the munitions at al-Qaqaa in January 2003 but has not been allowed back into Iraq since the invasion.
Analysts say the theft raises the possibility that some explosives could have found their way into improvised devices used against US-led forces in Iraq.
The lost explosives consist mainly of 195 tons of HMX (high melting explosives) and 141 tons of RDX (cyclonite) - both key components in plastic explosives.