David Kay US arms inspector
Mr Powell's comments come in the wake of the resignation of the leader of the U.S. group that's been searching for banned weapons in Iraq.
David Kay, the head of the American weapons inspection team, resigned saying that he did not believe the country had any weapons of mass destruction.
Mr Kay said there was no evidence that Iraq possessed large stockpiles of chemical or biological weapons.
His comments are likely to embarrass President George W Bush, who again insisted earlier this week that Iraq had actively pursued dangerous arms programmes up to the start of the invasion last March.
Mr Kay said he did not think Iraq had been involved in large-scale production of such weapons since the end of the first Gulf War in 1991.
The Bush administration's central argument for going to war against Iraq last year was that Baghdad had weapons of mass destruction that could threaten the United States and its allies.
