Washington (CNN) Ousted Navy Secretary Richard Spencer, who was forced out of his role Sunday after President Donald Trump's intervention in a war crimes case , said in an interview Monday that the President's actions send a message that "you can get away with things."

"What message does that send to the troops?" Spencer said of Trump's actions to CBS Evening News . "That you can get away with things. We have to have good order and discipline. It's the backbone of what we do."

Spencer's comments came the day after Secretary of Defense Mark Esper "fired" him for going outside his chain of command by proposing a "secret agreement with the White House," according to a senior defense official. Spencer appeared to be seeking a way to resolve a standoff between the Pentagon and White House over Navy SEAL Eddie Gallagher's case.

Gallagher had been convicted of bringing discredit to the armed services after posing next to a dead ISIS fighter's body, which is against regulations. Earlier this month, Trump reversed Gallagher's demotion and later tweeted he wouldn't let the Navy punish Gallagher in its ongoing review of whether he should be kicked out of the SEALs.

Behind the scenes, Spencer proposed to the White House that Gallagher's review go ahead but offered a secret guarantee that Gallagher would be allowed to keep his status as a Navy SEAL, according to the senior defense official.

Spencer said Monday, "I will take the bad on me for not letting (Esper) know I did that" but insisted the Pentagon chief "was completely informed as to this because his chief of staff was briefed on it."

Pentagon spokeswoman Alyssa Farah told CNN in a statement Monday night that "neither Secretary Esper nor anyone on his staff was aware" of Spencer's back-channel efforts.

Reacting to Trump's comments earlier Monday calling Gallagher a "war fighter" and stating that he had "to protect" his war fighters, Spencer said he didn't think the President "really understands the full definition" of the term.

"A war fighter is a profession of arms," he said. "And a profession of arms has standards that they have to be held to and they hold themselves to."

Spencer's pointed criticism of Trump's intervention echoes his letter to the President acknowledging his termination , where he said the President was undermining the "key principle of good order and discipline."

"I cannot in good conscience obey an order that I believe violates the sacred oath I took in the presence of my family, my flag and my faith to support and defend the Constitution of the United States," Spencer wrote.