"We're finding now that the capabilities are even more dispersed and disguised than we thought," Armitage said in a speech at the National Defense University.

"It's going to take us months to find this material, but find it we will."

The United States -- which ousted the regime of Saddam Hussein, claiming it was developing banned nuclear, biological and chemical weapons -- has come under fire in recent weeks because little proof of those claims has emerged.

Armitage dismissed the criticism, saying "I'm extraordinarily confident that Iraq had those capabilities.

"It's far too easy to hide and move these capabilities and far too difficult to find them."

US-led forces attacked Iraq March 20 after failing to convince the UN Security Council to take tougher measures to force Saddam to disarm. Iraq had been under UN sanctions stemming from its August 1990 invasion of neighboring Kuwait.

Saying the invasion was a last resort after all other means of disarmament had failed, Armitage called for more effective international efforts to stop proliferation of nuclear, biological and chemical weapons.

"Iraq is an object lesson that can happen if you leave the problems of proliferation to the solutions of the past," he said.

SPACE.WIRE