The News newspaper quoted unnamed sources as saying that at least 35 US special forces soldiers had been killed and many had been injured in a firefight with pro-Taliban troops in southern Afghanistan yesterday.
"The story is absolutely false," Pentagon spokesman Lieutenant Colonel David Lapan said.
"We did not have any soldiers killed in Afghanistan yesterday."
He said so far, the United States had no combat casualties in Afghanistan whatsoever.
"This story is one more example of the lies the Taliban continue to tell," Lapan added.
The News reported that the Americans took heavy casualties in an attack launched on Thursday on the Taliban militia and troops of the al Qaeda network of terror suspect Osama bin Laden.
The US troops were backed by helicopter gunships in the attack "but were caught by surprise and had to withdraw quickly," the daily said.