"But the idea that we'll wake up tomorrow and Iran will have a nuclear weapon is an idea that isn't supported by the facts as we have seen them so far."
ElBaradei's comments come as Iran annocuned that it was ready for fresh talks with world powers over its nuclear programme, which the West says is a cover for building nuclear weapons.
"About Iran, I've been told, 'Mind your own business; you're a technician' ... I'm neither a custodian nor a technician. I'm merely someone who is trying to do his job"
Tehran denies this and insists its nuclear programme is for purely civilian purposes.
In a report last week, the IAEA said that Iran had slowed production of enriched uranium, which can be used to make a nuclear bomb, and agreed to tighter monitoring of its enrichment plant.
The US downplayed the report, saying that Iran was still not co-operating fully with the UN inspectors.
Israel's Haaretz newspaper said the report did not include a classified annex that incriminated Iran.
Israel has long been critical of ElBaradei, calling for him to be fired in 2007.
ElBaradei, who - along with the IAEA as an institution - won the Nobel peace prize in 2005, rejected the criticism.
"About Iran, I've been told, 'Mind your own business; you're a technician.'
"And yet, at other times, on other matters, I have been told that I'm the custodian of the nuclear Non-Proliferation Treaty - sometimes by the very people who tell me to mind my own business when it comes to Iran," he said.
"I don't put much stock in either designation. I'm neither a custodian nor a technician. I'm merely someone who is trying to do his job."
ElBaradei steps down at the end of November, handing over to Yukiya Amano, a veteran Japanese diplomat.