By Laura MacInnis GENEVA, Dec 5 (Reuters) - The latest U.S. intelligence findings on Iran make a military attack on Tehran unlikely in the near future, former chief United Nations arms inspector Hans Blix said on Wednesday. The Swede, who also headed the International Atomic Energy Agency (IAEA), said he was "surprised" to learn of the sceptical assessment of Iran's nuclear capabilities released this week by U.S. intelligence agencies. "The main result is that it has excluded that there will be any military action in the intermediate future," Blix told reporters at the United Nations offices in Geneva. "An armed act against Iran is not credible, cannot happen after this, in this period over the next few years." The National Intelligence Estimate backed down from a 2005 assertion that Iran was determined to develop a nuclear weapon, as the White House has argued, and said instead that Tehran froze its nuclear weapons programme in 2003. Washington's decision to invade Iraq in 2003 was justified mainly on the basis of U.S. intelligence reports concluding -- incorrectly -- that Iraq had chemical and biological weapons and was developing a nuclear weapon. Blix was chief U.N. inspector for Iraq after 16 years as head of the IAEA. Blix said the new report, which concluded it was not clear whether Iran now intends to develop nuclear weapons, might reflect an unwillingness by the Central Intelligence Agency (CIA) and others to be held responsible for another "anticipatory" attack. With the United States entering an election year where public discontent over the war in Iraq is taking centre stage, the report provided political benefits too, he said. "Maybe it is very welcome to have a picture coming out of the intelligence services that it is not warranted," he said, referring to the justification for an attack on Iran. U.S. President George W. Bush has raised the spectre of World War Three if Iran acquired a nuclear weapon. Blix said it was important that the U.S. findings be backed up with further investigations and analysis, and stressed the grounds of the conclusions reached ought to be made more clear. "As an inspector I learned to be sceptical about everything. I would like to see evidence. He called for negotiations between Iran and Western powers to broker a long-term resolution to the nuclear issue. "I believe that one must try diplomacy and that there is now room for it," Blix said. "Before you have tried to talk, I don't think you should give up the possibility of agreement." (Editing by Robert Woodward)