"We will never stop until we avenge the death of all who are killed, injured, widowed and orphaned in Palestine and throughout the Islamic world," said Ayman al-Zawahiri in a new 10-minute audio recording released today on extreme Islamist Web forums.
The message is entitled "The Massacre in Gaza and the Siege of the Traitors".
Zawahiri refers directly to President-elect Barack Obama saying he has partnered with Egyptian President Hosni Mubarak, whom Zawahiri labels as a traitor to Islam.
"What you are facing today is just occupation and settlement that is limited to one area or one country, but is part of a series in the Crusaders war against Islam," says Zawahiri. "These air strikes are a gift from Obama before he takes office, and from Hosni Mubarak, the traitor who is the primary partner in your siege and murder."
To the Palestinians he says: "Be strong and persist in the way of Jihad. The whole Muslim ummah is united with you."
He also vows to carry out al Qaeda's repeated threat that the United States will not live in peace until Palestine does.
"We are at work to carry out the promise of our fighting sheikh Osama Bin Laden (may Allah protect him) who promised that America will not live in peace in their dreams before we live in peace in Palestine, and until all the forces of the infidels leave the lands of Muhammed," Zawahiri says.