WASHINGTON (AP) — Defense Secretary Mark Esper said Monday that President Donald Trump gave him a direct order to allow a Navy SEAL accused of war crimes to retire without losing his SEAL status.

Esper told reporters at the Pentagon that Trump's order was the reason he announced Sunday that Chief Petty Officer Edward Gallagher would be allowed to retire with his Trident Pin, retaining his status as a SEAL.

Last week Trump had tweeted that he wanted Gallagher to be allowed to retire as a SEAL, but Esper's comments Monday revealed that Trump had given the defense secretary a direct order to make this happen.

Gallagher was acquitted of murder in the stabbing death of an Islamic State militant captive but convicted of posing with the corpse while in Iraq in 2017.

In his remarks, Esper also made the extraordinary accusation that Navy Secretary Richard Spencer last week had secretly offered to the White House to rig the Navy disciplinary process to ensure that Gallagher not lose his Trident. He didn't say how.

"No. I asked, and I never got an answer," Esper said.

Esper fired Spencer on Sunday, saying he had lost trust in him. Spencer has not responded to requests for comment on Esper's accusation. However, in a letter Sunday to Trump acknowledging his firing, Spencer gave a different version of his thinking.

Spencer said he could not in good conscience follow an order that he believed would undermine the principle of good order and discipline in the military – suggesting that he had been -- or expected to be -- ordered to stop the peer-review process for Gallagher.

Esper said he remains concerned, based on the Gallagher case and other trouble with battlefield behavior by the military, that soldiers, sailors, airmen and Marines are not properly and fully trained in ethical standards. He said he had ordered the Pentagon's legal office to review how the military educates and trains service members on wartime ethics and the laws of armed conflict. The review also will look at how the services monitor, investigate and adjudicate adherence.

In announcing Sunday that he had dismissed Spencer, Esper said he acted after learning of Spencer's secret plan to guarantee the outcome of the Navy SEAL peer-review board that was scheduled to convene Dec. 2 with the goal of recommending whether Gallagher should be allowed to retain his Trident.

Spencer had "proposed a deal whereby if the president allowed the Navy to handle the case, he would guarantee that Eddie Gallagher would be restored to rank, allowed to retain his Trident and permitted to retire," Esper said.

This was "completely contrary" to what Esper and the rest of the Pentagon leadership had agreed to, he said, and contrary to Spencer's public position that the Navy disciplinary process should be allowed to play out with no interference.

Esper said he had previously advocated for allowing the Navy peer-review board go forward Dec. 2. But when Trump gave him a "verbal instruction" Sunday to stop the process, he did so.

"The commander in chief has certain constitutional rights and powers which he is free to exercise, as many presidents have done in the past," Esper said. "Again, these are constitutional powers."

Esper did not say explicitly that he disagreed with Trump's order.

Once Trump gave the order, Esper said he responded, "Roger. I got it."

"I can control what I can control," he told reporters. The president, he said, "has every right" to issue such an order.

Esper said he had been "flabbergasted" when he learned at the White House on Friday that Spencer had gone behind his back to propose a secret deal.

The White House did not immediately respond to a request for comment.

Esper said that when he called the Navy secretary, "he was completely forthright in admitting what had been going on."

The next day, Saturday, Esper called Trump to tell him that he intended to fire Spencer and Trump supported the decision.

On Sunday afternoon Esper called Spencer and told him he was being fired. Spencer "took it in stride" and said he would have a resignation letter to him within 30 minutes – "and he did."

In that letter, Spencer made no mention of what Esper called Spencer's secret deal with the White House.

Esper said it was best, under the extraordinary circumstances set in motion last week, that the Gallagher review board not proceed as planned. He said he believes in the military justice system, but in this case it had become untenable.

"As professional as they are," he said of the board members, "no matter what they would decide, they would be criticized from many sides, which would further drag this issue on, dividing the institution. I want the SEALs and the Navy to move beyond this now, fully focused on their warfighting mission."