Weighing in forcefully on the issue for the first time since the program was disclosed last week, Bush said the revelation "does great harm" to the nation and makes it harder to track terrorists.

Bush made the comments in a brief question-and-answer session with reporters after a meeting at the White House with private organizations that support the U.S. military in Iraq and Afghanistan.

Responding to a question about the program, run by the Treasury Department, Bush said Congress was briefed about it, "and what we did was fully authorized under the law."

He added emphatically, "And the disclosure of this program is disgraceful. We're at war with a bunch of people who want to hurt the United States of America, and for people to leak that program and for a newspaper to publish it does great harm to the United States of America."