http://www.cnn.com/2006/WORLD/meast/11/ ... index.html

BAGHDAD, Iraq (CNN) -- A purported audio recording by the leader of al Qaeda in Iraq vows to step up the group's fight against the United States, saying, "We haven't had enough of your blood yet."

The recording was posted Friday on an Islamist Web site and the speaker is identified as Abu Hamza al-Muhajir, successor to Abu Musab al-Zarqawi.

"Come down to the battlefield, you coward," the speaker says on the recording, which CNN cannot independently confirm as the voice of al-Muhajir.

Calling President Bush a "lame duck" and labeling outgoing U.S. Defense Secretary Donald Rumsfeld a "coward," the speaker tells Bush not to "run away as your lame defense secretary ran away," referring to Rumsfeld's resignation Wednesday.

Critics of the U.S.-led war in Iraq have laid much of the blame for its problems on Rumsfeld. The war's growing unpopularity contributed to the unseating of the Republican Party in both chambers of Congress in Tuesday's election. (Watch Rumsfeld acknowledge what's going wrong -- 2:23)

Much of the Iraqi insurgency has been blamed on al Qaeda in Iraq, whose former chief al-Zarqawi was killed in a U.S.-led airstrike in June.

The speaker on the tape vows that al Qaeda in Iraq will not stop its jihad "until we sit under the olive trees in Rumiya after we blow up the wicked house known as the White House." He says the first phase of the jihad is now over, and that the next phase -- building an Islamic nation -- has begun.

"The victory day has come faster than we expected," he says. "Here is the Islamic nation in Iraq victorious against the tyrant. The enemy is incapable of fighting on and has no choice but to run away."

The speaker claims his al Qaeda army has 12,000 soldiers -- with 10,000 more waiting in the wings to join them.

And he pledges those troops to the service of the Mujahedeen Shura Council and the Islamic Nation of Iraq. He calls on other insurgent groups in Iraq to join with them.

"We have to be unified by the sword, even though disagreements exist between us," al-Muhajir said.

"Go where God has ordered you to go and know that we are with you. We are your soldiers and your men," he says.