"Some people have guessed what's in the report and concluded that going in to Iraq was a mistake. I strongly disagree," Bush said.
The National Intelligence Estimate report, excerpts of which were published by the New York Times newspaper last weekend, said that analysis by the 16 US spy agencies concluded the Iraq war had spread Islamic radicalism and made the overall terrorism problem worse.
However, Bush said that using the report to attack his administrations policies was "naive".
"I think it's a mistake for people to believe that going on the offense against people that want to do harm to the American people makes us less safe," he said.
The US president, who said he would declassify parts of the report, also said that it was leaked for political reasons ahead of the US mid-term elections in November.
"Here we are coming down the stretch in an election campaign and it's on the front page of your newspapers," Bush said.
"Somebody took it upon themselves to leak classified information for political purposes."
Leading Democrat politicians have urged the US government to publish the report, which they say shows the Bush administration mishandled the 2003 invasion of Iraq and ensuing fighting.