US Treasury Secretary John Snow has defended a secret program which has tracked millions of financial transactions across the world for years, claiming it was not invasion of privacy but "government at its best."
Snow told a news conference the program, run by the CIA and overseen by the Treasury Department, was "responsible government, it's effective government, it's government that works."
"It's entirely consistent with democratic values, with our best legal traditions," Snow said.
The program, which has been going on since shortly after the 2001 terror attacks, drew protests from Democrats in Congress, who said it raises concerns about intrusions on privacy and who saw it as the latest step in an aggressive Bush administration expansion of executive-branch powers.
Snow defended the newly disclosed program, saying it was an effective tool in tracking the financial operations of terrorists.
"By following the money we've been able to locate operatives, we've been able to locate their financiers, we've been able to chart the terrorist networks and we've been able to bring the terrorists to justice," he said.
"If people are sending money to help al-Qaida, we want to know about it," Snow said.
He said Congress had been briefed on the program.
At the White House, presidential spokesman Tony Snow said the focus had been shutting off terrorist financing. "It's a good thing to shut off the spigot, the financial spigot," he said. "It does seem to be working."
The US government used powers of subpoena to compel the Brussels-based banking co-operative, the Society for Worldwide Interbank Financial Telecommunication (Swift), to open its records, giving access to an extensive international financial data base.
Swift handles information from 7,800 financial institutions in more than 200 countries.
The co-operative, based in Belgium, handles financial message traffic from thousands of financial institutions in more than 200 countries.
"It's important to understand that very significant protocols and safeguards have been put in place in a cooperative way between Swift and the Treasury Department," Snow said.
He said that access to the data that had been collected was limited to people with appropriate security clearances.
Snow declined to give specific examples of where the program had been successful in shutting off terrorist financing, but said that he had assured himself that it was working.
Barry Steinhartdt of the American Civil Liberties Union, called the program a "frightening invasion of civil liberties" while Edward Yingling of the American Bankers Association said banks were working to strike the right balance between "protecting customer privacy and stopping terrorist financing."
James Nason, an official with the Swiss Bankers Association, said his group was surprised to hear about the US effort. "We had no idea this was going on at all," he said.
The administration used broad subpoena powers to get access to the data.