US President George W Bush will make a televised address within hours after four hijacked planes destroyed the World Trade Center, the Pentagon and an area in Pittsburgh this afternoon.
CNN reported that President Bush is expected to begin his address at around 2 a.m. [Irish time].
President Bush earlier made two short statements since the attacks in which thousands of people are feared to have killed.
"Today we've had a national tragedy," he said, adding that "terrorism against our nation will not stand".
President Bush then flew abruptly to Barksdale Air Force Base in Louisiana where he said the US had taken all appropriate steps to protect the American people and would hunt down and punish those responsible for the attacks.
"Make no mistake, the United States will hunt down and punish those responsible for these cowardly acts," President Bush said at the air force base.
"Freedom itself was attacked this morning by a faithless coward," President Bush said. "Freedom will be defended".
As a security precaution Bush then took off again for Offutt Air Force Base in Nebraska, where he held a teleconference with top national security aides.
After a brief stay in Nebraska, President Bush again boarded Air Force One and headed back to Washington this afternoon.