"No, I'm a little busy, these days, actually doing my job, you know?", Mattis told journalists when asked whether he intended to peruse Michael Wolff's book, Fire and Fury: Inside the Trump White House.
"No, I don't ‐ I don't ‐ I purposely don't read that. And, if it's a book with my name in it, the aide puts sticky ‐ double stickies over it, so I don't read about myself," he added during a media opportunity.
This is Mattis' second jocular exchange with the press pool in several days.
On Thursday, he shut down a reporter's question regarding President Trump's tweet comparing the size and power of his "nuclear button" to that of North Korean dictator Kim Jong Un.
"My job as the secretary of defense is to make certain that we have forces ready to defend this country," Mattis said.
"But with all due respect, Mr. Secretary...," a member of the gaggle interjected.
"That always preludes something that is perhaps less than due respect from you, Barbara," Mattis replied. "Go ahead, please."