The radical Muslim cleric Anwar Al-Awlaki, whose killing has been approved by President Barack Obama, today taunted the American President and the United States military in an audio address posted online.

"Imperial hubris is leading American to its fate: a war of attrition, a continuous hemorrhage that would end with the fall and splintering of the United States of America," said Awlaki.

The site for the audio message features a picture of him juxtaposed with those Major Nidal Hassan, accused of the Ft. Hood shootings, and Omar Farouq Abdulmutallab, charged with the attempted bombing of an American jetliner on Christmas Day, 2009.

A U.S. counter-terrorism official said there's no reason to believe the voice on the tape isn't Awlaki, and said the message contained "well-worn themes of hatred, violence and attempts at fear mongering. It's not just extremist bravado, it's trash."

The American born and educated cleric also called on Muslims in the U.S. to do as he did in waging jihad against the U.S.

"I could not reconcile between living in the US and being a Muslim, and I eventually came to the conclusion that jihad against America is binding upon myself, just as it is binding on every other able Muslim," said Awlaki in the message, speaking in English.

Awlaki has been on the run since late last year when he was linked with both Major Hassan and Abdulmutallab. U.S. officials have told ABC News and other news agencies that the President approved efforts to target Awlaki with a missile strike in Yemen, where he is believed to be hiding.

Message from Anwar Al-Awlaki

In the message today, he makes no secret of his ties to the two men, Hassan and Abdulmutallab, accused of terror attacks on U.S. targets.

"America refuses to admit that its foreign policies are the reason behind a man like Nidal Hassan, born and raised in the US, turning his guns against American soldiers," said Awlaki who was in extensive e-mail contact with Hassan prior to the Ft. Hood shootings.

Abdulmutallab met with Al-Awlaki in Yemen prior to boarding a flight to the U.S. with a bomb in his underpants, according to American officials.