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.

The team led by U.S. President Donald Trump's national security adviser, Mike Waltz, set up at least 20 group chats on the commercial Signal app to coordinate official work on issues involving China,

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.