President Donald Trump's behavior can be so erratic that most top administration officials have pre-written resignation letters ready to submit, an anonymous author claiming to be a senior official in the Trump administration says in a book scheduled to be published this month.

To complicate matters, the president's decision-making abilities are getting worse with time, according to excerpts of "A Warning" that were obtained and read Thursday night on MSNBC's "The Rachel Maddow Show."

The cover of 'A Warning,' a book said to be by an anonymous senior Trump administration official, which is scheduled to be published on Nov. 19. Twelve

The author, described only as "a senior Trump administration official," is the same person who wrote an op-ed in The New York Times last year headlined, "I am part of the resistance inside the Trump administration." The column said "many of the senior officials in his own administration are working diligently from within to frustrate parts of his agenda and his worst inclinations."

The information is coming from an anonymous source, and NBC News does not know who the writer is nor whether they were in a position to have witnessed what they say transpired.

In the book excerpts, the author describes near-daily "five-alarm fire drill" that leads senior officials to cancel plans and race to the White House to intercept Trump before he can enact his latest "wacky or destructive idea."

"Staff throw up the Bat-Signal, calling a snap meeting or a teleconference. 'He's about to do something,' one warns the group, explaining what the president is about to announce.

"'He can't do this. We'll all look like idiots, and he'll get murdered for it in the press,' another exclaims.

"'Yeah, well, I'm telling you he's going to do it unless someone gets to him fast,' the first warns. 'Can you cancel your afternoon?'"

As Trump's presidency has progressed, his officials have been given increasingly less notice of the president's decisions, says the author, who writes: "He's less inclined to preview his decisions today."

The National Security Council, in particular, found the Trump process to be a difficult adjustment, the author writes.

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"If the aim was to educate this new commander in chief, they couldn't submit a fifty-page report entitled something like 'Integrated National Strategy for Indo-Pacific Partnership and Defense,' expect him to read it, and then discuss it,' according to the excerpts.

"That would be like speaking Aramaic to Trump through a pillow; even if he tried very hard to pay attention, which he didn't, he wouldn't be able to understand what the hell he was hearing."

The author writes that even Trump's own family isn't immune to his whims.

"It isn't beneath him to attack his own family members, too. 'Jared, you don't know what you're talking about, okay? I mean seriously. You don't know,'" the book quotes him as saying.

"Seeing this type of behavior was both educating and jarring to the burgeoning Steady State. It was a visceral lesson that we weren't just appointees of the president," according to the excerpts. "We were glorified government babysitters."

In excerpts published separately by The Washington Post, the author likens Trump to "a twelve-year-old in an air traffic control tower, pushing the buttons of government indiscriminately, indifferent to the planes skidding across the runway and the flights frantically diverting away from the airport."

"I've sat and listened in uncomfortable silence as he talks about a woman's appearance or performance," according to the Post's excerpts.

"He comments on makeup. He makes jokes about weight. He critiques clothing. He questions the toughness of women in and around his orbit. He uses words like 'sweetie' and 'honey' to address accomplished professionals. This is precisely the way a boss shouldn't act in the work environment."

NBC News has not seen the excerpts published in the Post nor has it been able to confirm the contents of what the newspaper reported.

Trump has called the writer "gutless" and has questioned whether the person really exists.