The shutdown of research at Fort Detrick is likely to last several months, she also told the New York Times.
This is not the first time the lab has been temporarily shut down due to failures in handling the dangerous pathogens inside.
In 2009, research at Fort Detrick was suspended because it was discovered it was storing pathogens which were not listed on its inventory.
The regulations on keeping close track of hazardous biological material were tightened after the 2001 anthrax attacks, which saw five people die after spores were posted to several media newsrooms and Democratic senators.
The FBI’s chief suspect in the 2001 case, Bruce Ivins, was a senior biological weapons researcher at Fort Detrick. He killed himself in 2008, shortly before the FBI was planning to charge him with the attacks.