A US soldier was killed by a roadside bomb in southern Afghanistan, where thousands of troops are conducting anti-insurgency operations ahead of upcoming elections, the military said Thursday. The soldier died when his vehicle was hit by an improvised explosive device, or IED, on Wednesday, a statement from the NATO-led International Security Assistance Force (ISAF) said. The statement quoted Captain Jon Stock, a US spokesperson, who confirmed the dead soldier was American. It gave no further details. US Marines have been pressing a major offensive in the southern province of Helmand ahead of the landmark August 20 presidential and provincial council elections.