Washington (CNN) Attorney General William Barr said special counsel Robert Mueller was "a bit snitty" in his letter expressing misgivings about the attorney general's letter to Congress summarizing Mueller's findings.

At a Senate Judiciary Committee hearing on Wednesday, Barr brushed off the criticisms in a new letter from Mueller , in which the special counsel objected to Barr's initial four-page letter to Congress. Mueller's letter showed the former FBI director felt Barr's letter to Congress didn't fully capture his 448-page report.

"You know, the letter's a bit snitty, and I think it was probably written by one of his staff people," Barr said.

A spokesman for the special counsel, Peter Carr, declined to comment to CNN when asked about Barr's characterization.

The Washington Post first reported Mueller's letter to Barr. CNN later obtained the full letter.