The package was found at 7:30 a.m. by Capitol Police patrolman, The Hill reported.
As of 9:30 a.m. the Capitol Police department was preparing to transport the item, spokeswoman Sgt. Kimberly Schneider said.
"It has been loaded into a specialized truck operated by our bomb squad," she told The Hill. "It will be transported to Quantico, VA [with a] Virginia State Police escort, to be rendered safe."
The area cordoned was to remain closed until police cleared the scene, Schneider said.