Dozens of former Republican national security officials have signed a letter on Monday saying a Donald Trump presidency would "put at risk our country's national security and well-being."

"None of us will vote for Donald Trump," the letter, which was published Monday by the New York Times, says. The authors then go on to characterize the billionaire as unfit for the Oval Office, saying he lacks the moral authority, judgement and foreign policy expertise.

"Unlike previous Presidents who had limited experience in foreign affairs, Mr. Trump has shown no interest in educating himself," the letter said. "He continues to display an alarming ignorance of basic facts of contemporary international politics."

The letter features the signatures of many former George W. Bush cabinet members and policy advisors, including former CIA and NSA director Michael Hayden, former intelligence chief John Negroponte and former Homeland Security secretary Tom Ridge.

Democratic presidential nominee Hillary Clinton's argument that Trump lacks the stable temperament to control the U.S. nuclear arsenal also made its way into the statement, but several signatories said the Clinton campaign had no role in drafting it, the New York Times reported.

"A President must be disciplined, control emotions, and act only after reflection and careful deliberation," the letter said. "In our judgement, Mr. Trump has none of these critical qualities. He is unable or unwilling to separate truth from falsehood. He does not encourage conflicting views. He lacks self-control and acts impetuously."

The publication of this anti-Trump rhetoric follows a tumultuous week for Trump, and just after the Democratic party had already appeared to shift American sentiment their way with the help of a carefully-executed convention in Philadelphia.

Some Republicans have gone so far as to endorse Clinton. For example, outgoing New York Rep. Richard Hanna, a Republican, said last week that he will be voting for the Democratic nominee in November.