The State Department said Friday that the FBI has asked the department to halt its internal investigation into emails sent or received by Hillary Clinton while she led the department, emails that are now deemed to contain "top secret" information.

State had been reviewing whether the information was deemed top secret at the time it was sent, or whether the information only became top secret later. But State Department spokesman Elizabeth Trudeau said the FBI asked the department to stop so as not to interfere with the FBI's own investigation.

She said State asked the FBI for a ruling in February on whether it should proceed, and that the FBI told State to stand down on its review sometime in March.

"We contacted the FBI to solicit a judgement from them as to the best path forward," Trudeau told reporters when asked about the review of the 22 emails that included "top secret" information. She didn't clarify if the decision affected hundreds of other emails that included classified information.

"The FBI communicated to us that we should follow our standard practice, which is to put our internal review on hold while there is an ongoing law enforcement investigation underway," she said.

"Of course, we do not want our internal review to complicate or impede the process of their ongoing law enforcement investigation," she added. "Therefore, the State Department at this time is not moving forward with our internal review."

Trudeau had no comment on whether the move might be a sign that the FBI is preparing criminal charges against Clinton or any of her aides.

"I wouldn't read anything into it," she said.

She also said the internal review would continue once the FBI's investigation is completed.

The issue of when the information was deemed "top secret" or classified at the time is important, because it appeared in emails that were sent or received by Clinton on her private email system. The risk of sensitive information being disseminated likely increased once it appeared on Clinton's unsecure, private server.

Trudeau was pressed several times why State's internal review would have to stop, or how it might complicate the FBI's investigation, but offered little else.

"We don't want to complicate the law enforcement investigation, that takes priority," she said.