Speaking in Des Moines, Iowa, on Friday, Democratic presidential nominee Hillary Clinton said it is "imperative" that the FBI move quickly to explain its decision to further investigate newly discovered emails deemed possibly related to its earlier inquiry into her use of a private email server.

We are 11 days out from perhaps the most important national election of our lifetimes," Clinton said, according to a video of her remarks published by ABC News. "Voting is already under way in our country. The American people deserve to get the full and complete facts immediately."

More: Full coverage of FBI's decision to further investigate Clinton's emails 

FBI Director James Comey earlier Friday told congressional leaders that new information from an "unrelated case" has caused the agency to investigate new information. He said he did not know if the new information was significant or improper.

Various news outlets throughout the day reported additional details, including that the newly found emails did not come from Clinton herself, her private server, or from investigations into the apparent Russian hacking of the Democratic National Committee. The New York Times and others reported that the new information came from computers or devices owned by Clinton aide Huma Abedin and her estranged husband, former U.S. Rep. Anthony Weiner.

Clinton said Comey "himself has said he doesn’t know if the emails referenced in his letter are significant are not. I’m confident whatever they are will not change the decision reached in July."

Comey announced in July that there was no evidence of criminal wrongdoing, although he said Clinton made errors in judgment.