A senior U.S. defense official says Iraqi leader Saddam Hussein has ordered the execution of scientists and their families who cooperate with United Nations weapons inspectors.

Deputy Defense Secretary Paul Wolfowitz said the death threat to Iraqi scientists is just one more sign that Baghdad is not committed to disarmament.

Instead, Mr. Wolfowitz, speaking in New York, says Iraq remains committed to concealing what he calls its weapons of mass terror.

But Mr. Wolfowitz stressed that time is running out for Baghdad. "Baghdad must disarm, peacefully if at all possible, but by force if necessary." he said.

The senior defense official added that disarming Iraq of its chemical, biological and nuclear weapons programs is a crucial part of winning the war on terror.