Obama vows to battle Al-Qaeda on September 11 anniversary

President Barack Obama vowed Friday to renew the battle against Al-Qaeda as he marked the eighth anniversary of the September 11 attacks in 2001 amid rising public anxiety over the Afghan war.

Obama lamented that passing time had not dulled the pain of the loss of nearly 3,000 lives in a "terrible instant," as he led national commemorations of the world's worst terror attack for the first time as president.

"Let us renew our resolve against those who perpetrated this barbaric act and who plot against us still," Obama said at a ceremony at a memorial at the Pentagon military headquarters, which was hit by a hijacked plane.

"In defense of our nation, we will never waver," Obama said on a rainswept day so different from the crisp September morning when Al-Qaeda hijackers showered death and destruction on New York, Washington and Pennsylvania.

"In pursuit of Al-Qaeda and its extremist allies, we will never falter," said Obama, who has taken a strategic decision to escalate the increasingly unpopular war against the Taliban and Al-Qaeda remnants in Afghanistan.