When the president appealed to then FBI director Comey in an Oval Office conversation to drop the investigation into former Trump adviser Michael Flynn, saying "I hope you can let this go," Comey said he struggled to find a way to respond.

"I was so stunned by the conversation that I just took it in, and the only thing I could think to say," Comey said. "I was playing in my mind, what should my response be?"

According to his own report, he spoke positively of Flynn without saying he'd do anything with the investigation. The president has since suggested that he recorded those conversations.

"Lordy, I hope there are tapes," Comey concluded.