The Pentagon's inspector general announces that Hegseth's use of Signal – which is encrypted but not approved for use with classified information – will be investigated.
The investigation will also examine how other personnel in the defense department use the messaging service and to what extent the department's guidelines and processes are followed.
"Furthermore, we will investigate compliance with classification and registration requirements," writes Inspector General Steven Stebbins in a message to Hegseth.
Last week, The Atlantic magazine revealed that, among others, Pete Hegseth, national security adviser Mike Waltz, intelligence chief Tulsi Gabbard, and Vice President JD Vance had discussed the impending airstrikes against the Houthi movement in Yemen on Signal.
The Atlantic's editor-in-chief Jeffrey Goldberg had been invited to the chat group for unknown reasons.
