U.S. officials say a program to track, potentially, tens-of-thousands of financial transactions is an important part of anti-terrorist efforts carried out since the September 11, 2001, al-Qaida attacks in the United States.  There has been some congressional reaction to disclosure of the previously secret program.

After media reports detailed the existence of the program, approved by President Bush in the aftermath of the 2001 attacks, the White House and Bush administration officials came out strongly in defense of it.

Treasury Secretary John Snow says the examination of international banking transactions and other records has been a vital part of preventing new terrorism.

"We have never denied it.  In fact, beyond that, we have been open in making it clear that we do this," he said.  "And it is the responsible and right thing to do it.  We need to use lawful and legal tools available to us, given by Congress, to protect the citizens of our country."

U.S. officials say the program has been limited in scope, confined to tracing transactions of people suspected of having ties to al-Qaida or their associates.

It involves records from the Society for Worldwide Interbank Financial Telecommunication (SWIFT), a Brussels-based banking consortium, which, according to the Treasury Department, provided access to CIA and FBI officials and others to examine potential terrorist-related transactions.

U.S. Attorney General Alberto Gonzalez also defended the program, calling it legal.

At the White House, presidential spokesman Tony Snow ran down a list of descriptions of the program in media reports, and insisted the effort is a critical part of the war on terrorism.

"The program is a significant departure from typical practice," he said.  "Well, so was September 11.  And I think, everybody acknowledges that, in the wake of September 11, it became necessary to try to use every means at our disposal to try to figure out what terrorists were doing, and to try to track them down and to stop their activities."

While officials have been quick to defend the financial monitoring program, they also have expressed dismay that its existence was revealed by the media, saying this could hurt anti-terrorist efforts.

White House spokesman Snow told reporters Friday the program can be credited with helping to apprehend a key participant in the terrorist bombings in Bali, Indonesia.

Since 2001, members of Congress have been supportive of Bush administration efforts to eliminate sources of funding for terrorists.

However, Massachusetts Democrat Ed Markey questions how extensively the administration briefed lawmakers, and he asserts the data monitoring program violates Americans' constitutional rights.

"If the administration wants to fight terrorism legally, then it should ask for the authority it needs, and then follow the law that Congress passes, and appear before the courts of the U.S. to justify infringement into thousands or potentially millions of American's financial records," he said.  

Another program President Bush approved in the aftermath of the September 2001 terrorist attacks to monitor domestic telephone conversations without first obtaining a warrant, has been subject to similar criticisms.

Congressman Markey says, while the Bush administration may have notified lawmakers' congressional intelligence committees, it remains to be seen if panels dealing with homeland security were included in briefings on the financial data monitoring effort.