Sen. Mark Kelly (D-Ariz.) on Monday ripped President Donald Trump and Defense Secretary Pete Hegseth after the Pentagon launched a probe that could see him recalled to active duty to face a court-martial.

“I’ve been through a lot worse in service to my country. The president and Pete Hegseth are not going to silence me,” Kelly, a retired astronaut and U.S. Navy veteran, said at a press conference.

Kelly, who was among the group of Democratic veterans who urged military service members to disobey illegal orders in a video, emphasized why he won’t be intimidated by Hegseth and Trump, the latter of whom accused the lawmakers of “SEDITIOUS BEHAVIOR” and promoted calls for their executions.

Kelly noted that when Trump was writing a birthday message for Jeffrey Epstein and peddling birther conspiracy theories about former President Barack Obama, he was busy helping to recover the remains of those aboard the Space Shuttle Columbia disaster and supporting his wife, then-Rep. Gabby Giffords (D-Ariz.), after she was shot in the head during a 2011 assassination attempt.

Kelly called the Pentagon’s probe a “dangerous moment” for the U.S. and reiterated his past observations that Hegseth was “unqualified” for his post.

“He runs around on a stage like he’s a 12-year-old playing army, and it is ridiculous. It is embarrassing,” Kelly said.

This week, Hegseth has faced backlash after a Washington Post report claimed that he had ordered U.S. military forces to “kill everybody” in a strike on an alleged drug boat in the Caribbean ― an order that prompted a second attack to kill the survivors of the first strike. In response, Hegseth blamed the “fake news” for its “fabricated, inflammatory, and derogatory reporting,” and tried to make a meme about the scandal using a doctored image of Franklin the turtle from Paulette Bourgeois’ children’s book series.

“He’s putting out on the internet, turtles with rocket-propelled grenades. I mean, have you seen this? This is the secretary of defense. This is not a serious person,” Kelly said. “He should’ve been fired after Signalgate ― and then every single day after that.”