John Bolton, a national security adviser in the first Trump administration, is expected to enter a guilty plea Friday for mishandling classified information. File Photo by Kevin Dietsch/UPI | License Photo

June 26 (UPI) -- John Bolton, a national security adviser in the first Trump administration, entered a guilty plea Friday for mishandling classified information.

Bolton pleaded guilty to one charge of illegally retaining classified information in a Federal District Court in Greenbelt, Md., The New York Times, CNN and NBC News report citing unnamed sources familiar with the case. The accusation stems from personal notes on classified information that he used to write a book about Donald Trump's first presidency.

"I am your honor and I'm sorry for it," Bolton said when asked if he was guilty.

The memoir, The Room Where It Happened, was published in 2020.