Former FBI Director James Comey testified Thursday before the Senate Intelligence Committee. Comey explained to Sen. Mark Warner why he was prompted to document his conversations with President Trump.

What follows is a transcription of their conversation:

WARNER: Now, you said after that briefing you felt compelled to document that conversation that you, actually started to document it as soon as you got into the car. Now, you have had extensive experience at the Department of Justice and at the FBI. You have worked under presidents of both parties. What was it about that meeting that led you to determine that you needed to start putting down a written record?

COMEY: A combination of things. I think the circumstances, the subject matter, and the person I was interacting with. Circumstances first, I was alone with the President of the United States. ... I was talking about matters that touch on the FBI's core responsibility and that relate to the President —President-elect personally, than nature of the person. I was honestly concerned he might lie about the nature of our meeting, so I thought it was important to document that combination of things I never experienced before. But it led me to believe I have to write it down and I have to write it down in a very detailed way.

WARNER: I think that's a very important statement you just made.