On Wednesday The Atlantic published more complete versions of the messages, with some redactions for security purposes, after President Trump said "it wasn't classified information."

The Pentagon referred Newsweek to the National Security Council when asked for comment on the apparent security lapse. The NSC did not immediately respond to a request for comment, but a spokesperson for the agency previously confirmed to Goldberg the Signal group chat "appears to be an authentic message chain."

Why It Matters

A wave of U.S. airstrikes hit Houthi targets on March 15 killing 53 people according to Yemen's health ministry, which is run by the group. Additional airstrikes followed in the subsequent days.

Details of U.S. military operations are not supposed to be conducted over publicly available platforms such as Signal, and a number of security experts have said the chat group could have violated the Espionage Act. Ahead of the 2016 presidential election, Donald Trump focused heavily on Democratic rival Hillary Clinton's use of a private email server for official business as secretary of state.

What To Know

Newsweek has reproduced all the Signal group messages that were published by The Atlantic, either by being written out by Goldberg or included in the article as screenshots. It is unclear what proportion of the messages The Atlantic chose to make public, and some details were kept secret for security reasons.

Thursday, March 13

White House National Security Advisor Michael Waltz: "Team – establishing a principles group for coordination on Houthis, particularly for over the next 72 hours. My deputy Alex Wong is pulling together a tiger team at deputies/agency Chief of Staff level following up from the meeting in the Sit Room this morning for action items and will be sending that out later this evening.

"Pls provide the best staff POC [point of contact] from your team for us to coordinate with over the next couple days and over the weekend. Thx."