US President Barack Obama has been trying to shore up public support for the conflict in Afghanistan.
Thursday’s presidential election is widely seen as a major test of Obama’s revamped strategy.
Speaking to a military veterans’ group in Arizona, he insisted the United States is committed to stabilising the war-ravaged country.
“The insurgency in Afghanistan did not 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.”
Since taking office, Obama has shifted focus from the unpopular war in Iraq to Afghanistan – seeing it as his administration’s top foreign policy issue.
America has rushed 30,000 troops there this year.