US President Barack Obama is seeking to shore up public support for the war in Afghanistan as elections are held there on Thursday.

Obama told a group of veterans gathered at a convention the conflict in Afghanistan is "a war worth fighting".

Barack Obama, US President, said, "The insurgency in Afghanistan didn't just happen overnight, and we won't defeat it overnight. This will not be quick, nor easy. But we must never forget, this is not a war of choice, this is a war of necessity. Those who attacked America on 9/11 are plotting to do so again. If left unchecked, the Taliban insurgency will mean an even larger safe haven from which al-Qaeda would plot to kill more Americans. So this is not only a war worth fight, this is fundamental to the defense of our people."

(CCTV August 18, 2009)