WASHINGTON (CNN) -- Press Secretary Ari Fleischer said "the White House very much regrets" the decision to cancel holiday tours of the executive mansion, but he defended it as a necessary security measure for a "nation at war."

"We wish that the arrival of Christmas would mean that the terrorists would take time off, but it doesn't work that way," Fleischer said Tuesday.

Asked how the Bush administration could expect Americans to heed its calls for a normal life amid the holiday cancellations and restrictions, Fleischer said he thought they would understand.

"The public has a widespread recognition that the White House is a unique target," declared Fleischer, calling the building "probably terrorists' number one target."

http://www.cnn.com/2001/TRAVEL/NEWS/11/20/rec.whitehouse.tours/index.html