Retired U.S. Navy Admiral James Stavridis slammed Defense Secretary Pete Hegseth on Monday for his reported use of Signal to share highly sensitive military plans with Trump officials as well as family members and his attorney.

“There is absolutely no reason on the planet earth he should be doing that and he knows it,” said the former NATO Supreme Allied Commander of Hegseth’s use of the third-party messaging app in an interview with CNN’s Boris Sanchez.

“He’s a former major in the U.S. Army, he was trained throughout his time as a junior officer to protect and guard the nation’s secrets. He’s got to know that he has failed to do that.”

Hegseth — who shared details of upcoming attacks in Yemen in a Signal chat with senior Trump officials (and a journalist) — is reportedly close to being replaced in his post after The New York Times reported Sunday that he shared nearly identical details in a separate chat with his wife, brother and lawyer.

Stavridis argued that “Signalgate 2.0,” compared to the first chat involving high-ranking officials only to be “leaked inadvertently” to a member of the press, now involves “unclassified individuals who lack the need to know any of this.”

“So it’s gone from outrageous to truly egregious and it’s conduct that, frankly, is indefensible,” Stavridis said.

The former Fox News host — when asked about the reports of the second Signal chat on Monday — chided the media as he blamed “disgruntled former employees” for leaks at the Pentagon.

His comments arrive following a chaotic week at the Pentagon that saw Hegseth firing three of his advisers, who — in a joint statement — claimed that they didn’t know why they’d been fired.

“You can’t just fire people and expect loyalty from them on the far side of the bridge,” Stavridis stressed.

“So no, I’m not surprised about the blowback from firing people that you have hired. We ought to remember, these are folks that Secretary Hegseth hired, put on his team, he chose them, he’s worked with them in the past. I think it’s quite damning.”

Stavridis pointed to an op-ed recently penned by John Ullyot, a top Pentagon spokesman who resigned last week who claimed that those who were fired weren’t responsible for the leaks at the Defense Department.