"That they deceived us about the weapons of mass destruction, that's true. We were taken for a ride," Kwasniewski said Thursday.
He argued however that it made no sense to pull US-led coalition troops out of Iraq.
His comments marked the first time Poland has publicly criticized Washington's argument for invading Iraq and for winning support from Poland and other European allies such as Britain and Spain.
Poland heads up a 9,000-strong multinational force patrolling a swathe of Iraq south of Baghdad.
Warsaw itself has the fourth-largest contingent in the coalition, with around 2,500 soldiers.
Kwasniewski was speaking days after the prime minister-elect of Spain, Jose Luis Rodriguez Zapatero, said Madrid would withdraw its 1,300 soldiers from the Polish-led contingent by June 30, unless the United Nations (news - web sites) took over administration of Iraq.
The Polish head of state questioned the wisdom of pulling foreign troops from the strife-torn country saying such a move could have a counter effect.
"What would be the point of pulling the troops if it meant a return to war, ethnic cleansing and conflict in neighboring countries," he told a group of visiting French journalists.
"If we protest against the United States' dominant role in world politics and we withdraw our troops knowing they will be replaced by US soldiers, what would be the point of such a move?" he questioned.
He said he was disappointed by the new Spanish government's threat to withdraw its 1,300 soldiers.
"We cannot alter our mission to stabilize Iraq to one to destabilize the country," he said.
"Passiveness will lead us nowhere," he added.
