He said that it was "extraordinary that we would see something like this just 11 days out from a presidential election."
His statement noted that in July Comey announced the FBI would not recommend charges be brought against Clinton for her use of the server. It also criticized Republicans for "baselessly second-guessing the FBI."
Read the full statement below:
"Upon completing this investigation more than three months ago, FBI Director Comey declared no reasonable prosecutor would move forward with a case like this and added that it was not even a close call. In the months since, Donald Trump and his Republican allies have been baselessly second-guessing the FBI and, in both public and private, browbeating the career officials there to revisit their conclusion in a desperate attempt to harm Hillary Clinton's presidential campaign.
"FBI Director Comey should immediately provide the American public more information than is contained in the letter he sent to eight Republican committee chairmen. Already, we have seen characterizations that the FBI is 'reopening' an investigation but Comey's words do not match that characterization. Director Comey's letter refers to emails that have come to light in an unrelated case, but we have no idea what those emails are and the Director himself notes they may not even be significant.
"It is extraordinary that we would see something like this just 11 days out from a presidential election.
"The Director owes it to the American people to immediately provide the full details of what he is now examining. We are confident this will not produce any conclusions different from the one the FBI reached in July."