A photo taken this week showed Mike Waltz using an app that looks like—but is not—Signal to communicate with top officials.

Former national security adviser Mike Waltz was photographed using a Signal-like messaging app during Wednesday’s Cabinet ...

Former national security adviser Mike Waltz was photographed using a Signal-like messaging app during Wednesday’s Cabinet ...

In March, the editor of the Atlantic magazine revealed that national security adviser Michael Waltz had inadvertently ...

Waltz was at the center of the Signal chat controversy, in which a journalist was accidentally included in a discussion of ...

President Donald Trump's outgoing national security adviser Mike Waltz was photographed peaking at his phone under the table ...

Mike Waltz gave up one of the safer seats in Congress to serve as President Donald Trump’s national security adviser (Trump ...

Mike Waltz was photographed using Signal in a Cabinet meeting the day before Trump announced he was replacing him as national ...

Waltz was among high-ranking members of the administration who accidentally shared plans about a forthcoming U.S. military ...

President Donald Trump announced that Mike Waltz had been ousted as national security advisor. He was previously caught up in ...

Waltz inadvertently added The Atlantic's editor-in-chief to a group thread discussing sensitive national security matters.

America has been bombing Yemen for two decades. That conflict ultimately led to Waltz’s dismissal as national security ...