WASHINGTON (CNN) -- Democratic National Committee Chairman Howard Dean slammed former New York City Mayor Rudy Giuliani over his pre-9/11 preparation Thursday.

Dean's comments came after the GOP presidential hopeful's recent comments that a Democratic president would increase the risk of a terrorist attack.

"Rudy Giuliani was mayor of New York when 9/11 struck," Dean told CNN's Wolf Blitzer. "There was a previous terrorist attack. He had a number of years to do the things that a commission recommended they do and he didn't do them."

At a campaign event in New Hampshire on Tuesday, Giuliani said Democrats "do not understand the full nature and scope of the terrorists' war against us."

In the wide-ranging interview, Dean also clarified his recent comments that candidates would speak truthfully if media outlets did not cover them.

"I think there ought to be a free exchange between people and their candidates, and I don’t think you can always rely on the press to let the facts be known as the facts actually happened in the hall," Dean said.

At a Mortgage Bankers Association meeting earlier in the week, Dean said, "Politicians are incredibly careful not to say anything if they can possibly help it except if it is exactly scripted and if you want to hear anybody's true views you cannot do it in the same room as the press."

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