House Speaker Paul Ryan has formally asked the Director of National Intelligence James Clapper to remove Hillary Clinton's security clearance and prevent her from receiving classified intelligence briefings presidential nominees get on national security.

The Wisconsin Republican had said earlier this week that the presumptive Democratic nominee should not be permitted to get the classified briefings following FBI Director James Comey's announcement that Clinton's handling of such intelligence material as secretary of state was "extremely careless."

In his letter to Clapper, sent Wednesday, Ryan cites his own experience in receiving classified intelligence briefings as a formal vice presidential nominee. After her party formally nominates her at the Democratic convention later this month, Clinton will get similar briefings, Ryan says.

"There is no legal requirement for you to provide Secretary Clinton with classified information, and it would send the wrong signal to all those charged with safeguarding our nation's secrets if you choose to provide her access to this information despite the FBI's findings," Ryan writes.

Also on Wednesday, Ryan wrote to Comey requesting the FBI "release all of the unclassified findings from its investigation" into Clinton and her use of a private email server as secretary of state.

Comey is slated to testify Thursday morning before the House Oversight Committee on the probe into Clinton.