Hillary Clinton. REUTERS/Aaron Josefczyk MSNBC host Chuck Todd confronted Hillary Clinton after her meeting with the FBI amid an investigation into her email use at the State Department.

"Why do you believe you did not violate the law?" Todd asked, referring to rules regulating government employees' handling of classified information.

Clinton reiterated that she "never received nor sent any material that was marked classified" while she was secretary of state.

Some of the emails that had not been considered classified during Clinton's tenure were labeled as such after the fact.

Clinton dodged Todd's question about who gave her permission to operate a private email server to conduct government business. She insisted that no wrongdoing was committed. "I've released more than 55,000 pages of my emails for the public to read for themselves," she said, adding "I will continue to be as forthcoming as I can."

The presumptive Democratic presidential nominee said that she was "eager" to meet with officials handling the case, and said that she was pleased to "assist the department in bringing its review to a conclusion."

Clinton's FBI interview happened just days after Attorney General Loretta Lynch was roundly criticized for a meeting earlier this week with former President Bill Clinton aboard an airplane parked on an Arizona tarmac.

When asked about the meeting, Mrs. Clinton said, "I learned about it in the news and it was a short, chance meeting ... they did not discuss the Department of Justice’s review." She later added "hindsight is 20/20," acknowledging that the meeting between her husband the Lynch was viewed negatively.

It's unclear what the email investigation will yield, or when it will wrap up. Clinton first admitted in March 2015 that she used a private email server while working for the State Department. Federal authorities began their investigation in August.