WASHINGTON (Reuters) - Media reports that the United States has struck targets in Iraq are not accurate, a Pentagon spokesman said on Thursday, as Islamist militants advanced across northern Iraq.

"Press reports that U.S. has conducted airstrikes in Iraq completely false," Rear Admiral John Kirby said in a post on his Twitter feed. "No such action taken."

Kirby's statement came as U.S. officials said that the Obama administration has approved military air drops of humanitarian supplies in northern Iraq and is considering strikes against fighters from the Islamic State, an al Qaeda offshoot.

(Reporting By Missy Ryan; Editing by Sandra Maler)