President Trump removed Mike Waltz as national security adviser Thursday amid fallout from what’s known as “Signalgate,” in which Waltz added the editor of The Atlantic magazine to a group chat about Yemen war plans. Trump said he will instead nominate Waltz as ambassador to the United Nations, and has named Secretary of State Marco Rubio as interim national security adviser. A Reuters reporter snapped photographs of Mike Waltz using a modified version of Signal at a Cabinet meeting as recently as this Wednesday. He appeared to have recent exchanges with Secretary of State Marco Rubio, Vice President JD Vance and Director of National Intelligence Tulsi Gabbard.

The U.S. has struck Yemen on a near-nightly basis since mid-March, killing over 250 people, according to reports, though experts say the true death toll could be twice as high.