WASHINGTON— White House officials said Sunday they could not immediately authenticate a new audio message purportedly by al-Qaida leader Osama bin Laden that claimed responsibility for the plot to bomb a Detroit-bound airliner on Christmas Day.

But White House adviser David Axelrod told CNN's "State of the Union" that whatever the source, the message "contains the same hollow justification for the mass slaughter of innocents."

In the message released early Sunday, bin Laden threatened more attacks on the United States.

White House spokesman Robert Gibbs said "nobody's had a chance to authenticate that tape," and he declined comment on whether the U.S. believes bin Laden played any role in the Christmas incident.

Speaking on "Fox News Sunday," Gibbs said, "Everybody in this world understands that this is somebody that has to pop up in our lives over an audio tape because he's nothing but a cowardly murderous thug and terrorist that will some day — hopefully soon — be brought to justice."

The minute-long recording was carried by the Al-Jazeera Arabic news channel. Bin Laden addresses President Barack Obama and says the failed Christmas attack was meant to send a message similar to that of the Sept. 11 attacks.

State Department spokesman P.J. Crowley said that while bin Laden remains a "catalyst" for terrorist activities by groups affiliated with his organization, there is no indication that he or his lieutenants have a direct hand in ordering attacks.

"They offer strategic guidance and rely on their affiliates to carry out that strategic guidance," Crowley said in an interview. The audio tape made public Sunday offers no evidence that bin Laden's relationship with affiliates such as al-Qaida in the Arabian Peninsula, based in Yemen, has changed, Crowley said.

"He's trying to continue to appear relevant" by talking up an attempted attack by an affiliate, Crowley added. (AP)