A US solder was killed in Afghanistan, NATO said on Sunday, raising the American death toll to twice the number of those killed there in 2008, according to an AFP tally.

The NATO-run International Security Assistance Force (ISAF) said the soldier died from an improvised explosive device (IED), the biggest killer of foreign troops in the eight-year battle to contain a Taliban insurgency.

"An ISAF service member from the United States died following an IED strike in southern Afghanistan Saturday," the force said in a statement.

The death takes this year''s international military casualties in Afghanistan to 506, according to an AFP tally based on independent website icasualties.org which tracks military deaths in Afghanistan and Iraq.

Of those deaths, 310 have been Americans, according to the AFP tally. That figure compares with a total of 155 Americans given by icasualties for 2008.