White House National Security Advisor John Bolton and his deputy are trying to squeeze out U.S. Defense Secretary James Mattis by spreading rumors about his imminent departure, according to two well-placed sources.

Bolton and Mira Ricardel, the deputy national security advisor, who has repeatedly clashed with Mattis over Defense Department personnel appointments, believe the defense secretary is “not ideologically aligned” with President Donald Trump’s administration, according to one of the sources, a former senior defense official. The two are trying “to build the sense that he is done for,” the former official said.

“They have the knives out.”

One Trump administration official noted, “Mira and Bolton are the only ones who benefit if Secretary Mattis leaves.” The secretary is “highly regarded” within the cabinet and by lawmakers on both sides of the aisle, the official said.