Defense Secretary Pete Hegseth had the commercial messaging app Signal set up on a computer in his office at the Pentagon so that he could send and receive instant messages in a space where personal cellphones are not permitted, according to two people with knowledge of the matter.
Mr. Hegseth’s move facilitated easier communications in a building where cell service is poor and personal phones are not allowed in certain areas. It was first reported by the Washington Post.
The defense secretary has two computers in his office, one for personal use and one that is government-issued, according to one of the people with knowledge of the matter. Both spoke on condition of anonymity because of the sensitivity of the situation.
Mr. Hegseth had cables installed in early March so that he could connect a private computer to Signal, according to a second person with knowledge of the matter.
His confidential assistant and Col. Ricky Buria, his junior military aide, had the same Signal capability, the person said.
The latest revelation came after The New York Times reported that Mr. Hegseth had shared highly sensitive and detailed attack plans in a Signal chat group that included his wife, his brother and his personal lawyer hours before a mission was launched against Houthi targets in Yemen on March 15.
He had shared essentially the same information in a group chat with top national security officials, also shortly before the strikes. The fact of that conversation became public when The Atlantic reported that its editor, Jeffrey Goldberg, had been inadvertently included in the group chat.
Trump administration officials suggested there was no issue with Mr. Hegseth’s use of Signal in his office.
“The secretary of defense’s use of communications systems and channels is classified,” said Sean Parnell, the chief spokesman for the Pentagon. “However, we can confirm that the secretary has never used and does not currently use Signal on his government computer.”
Karoline Leavitt, the White House press secretary, called it “another nonstory,” noting that Signal is an app approved for government use.
The Pentagon’s acting inspector general announced earlier this month that he would review Mr. Hegseth’s Yemen strike disclosures on Signal.
Senator Roger Wicker, a Mississippi Republican who chairs the Armed Services Committee, and the committee’s senior Democrat, Senator Jack Reed of Rhode Island, requested the review. In a letter last month, the senators asked the inspector general to conduct an inquiry into whether Mr. Hegseth had shared sensitive or classified information in the national-security group chat.
The details about the strikes that Mr. Hegseth sent came from U.S. Central Command through a secure government system designed for transmitting classified information, according to an official and a person familiar with the conversations.
Besides the disclosures of the Signal chats, in the past month Mr. Hegseth has seen the dissolution of his inner circle of close advisers — military veterans who, like him, had little experience running large, complex organizations. Three members of the team he brought with him into the Pentagon were accused last week of leaking unauthorized information, and escorted from the building.
President Trump and White House officials have stood by Mr. Hegseth through both controversies related to Signal.
But Mr. Hegseth also irritated White House officials by booking himself for a Fox News interview on Tuesday morning, during which he accused fired advisers of making up stories about him.
White House officials have told him they want him to get the fractious situation with his staffing under control, according to a person with knowledge of the discussions.
