It’s a more extensive use of the app than previously reported and sheds new light on how commonly the Trump administration’s national security team relies on Signal.

Amid the backlash to the Trump administration’s use of the private messaging app Signal for sensitive U.S. military planning in Yemen, Politico reported Wednesday that national security adviser Mike Waltz’s team set up at least 20 such chats.

The national security adviser's use of the messaging app is under scrutiny after he mistakenly added a journalist to a sensitive chat.