A new audio message purportedly made by Osama bin Laden has the al-Qaeda leader claiming responsibility for the plot to bomb a Detroit-bound airliner last month on Christmas Day.
The man speaking on the tape, broadcast Sunday, also vows further attacks on the United States.
A White House adviser said he could not confirm whether the voice was actually that of bin Laden. 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."
The message suggests that bin Laden wants to show he remains in direct command of al-Qaeda's many branches around the world.
In the minute-long recording carried by Al-Jazeera, the man the Arabic news channel identifies as bin Laden addresses U.S. President Barack Obama, saying the attack was a message similar to that of Sept. 11 and more attacks against the U.S. would be forthcoming.
"The message delivered to you through the plane of the heroic warrior Umar Farouk Abdulmutallab was a confirmation of the previous messages sent by the heroes of the Sept. 11," the voice says.
"America will never dream of security unless we will have it in reality in Palestine," he says. "God willing, our raids on you will continue as long as your support for the Israelis continues."
On Christmas Day, Abdulmutallab, a Nigerian, attempted to blow up the Northwest Airlines flight he was sitting on as it approached Detroit Metro Airport from Amsterdam. But the bomb hidden in his underwear failed to explode.
He reportedly told federal agents shortly afterward that he had been trained and instructed in the plot by al-Qaeda operatives in Yemen.
Al-Qaeda in the Arabian Peninsula originally took credit for the attack, but the audio message seems to give bin Laden credit for ordering attacks, rather than just putting his seal of approval on events afterward.
Analysts had previously suggested that al-Qaeda's offshoots in North Africa, the Arabian Peninsula and elsewhere operate independently from bin Laden, who is believed to be somewhere in Afghanistan-Pakistan border region.
In the past year, messages identified as coming from bin Laden have concentrated heavily on the plight of the Palestinians in an apparent attempt to rally support across the region.
Many analysts believe that bin Laden is worried about Obama's popularity across the Middle East with his promises to withdraw from Iraq, so the al-Qaeda leader is focusing on the close U.S.-Israeli relationship.
The suffering of the Palestinians, especially in the blockaded Gaza Strip where 1,400 died during an Israeli offensive there last year, has angered many in the Arab world.
Israeli Foreign Ministry spokesman Andy David dismissed the latest al-Qaeda message and its attempt to link Israel with attacks on the U.S.
"This is nothing new, he has said this before. Terrorists always look for absurd excuses for their despicable deeds," he said.
The last public message purportedly from bin Laden appears to have been on Sept. 26, when he demanded that European countries pull their troops out of Afghanistan. The order came in an audiotape that also warned of "retaliation" against nations that are allied with the United States in fighting the war.
In the past, the CIA has usually confirmed Al Jazeera reports on tapes attributed to bin Laden.