The Pentagon’s acting inspector general has announced that he will review Defense Secretary Pete Hegseth’s use of the Signal messaging app to convey plans for a military strike against Houthi militants in Yemen.

The review will also look at other defense officials’ use of the publicly available encrypted app, which is not able to handle classified material and is not part of the Defense Department’s secure communications network.

“The objective of this evaluation is to determine the extent to which the Secretary of Defense and other DoD personnel complied with DoD policies and procedures for the use of a commercial messaging application for official business. Additionally, we will review compliance with classification and records retention requirements,” the acting inspector general, Steven Stebbins, said in a notification letter to Hegseth.