The challenge was made in an interview Saddam did with famous US journalist Dan Rather.
Saddam said the debate would be a chance for George W Bush to convince the world why there should be war with Iraq.
In the interview, Saddam also suggested he might not follow UN orders to destroy some of his missiles.
The UN says the powerful al-Samoud II missiles are banned because they can travel too far if fired.
Saddam's been given till Saturday to destroy them.