Top Trump administration officials mistakenly disclosed war plans in a messaging group that included a journalist shortly before the U.S. attacked Yemen's Iran-aligned Houthis, the White House said, following a first-hand account by The Atlantic.

Created by the entrepreneur Moxie Marlinspike, Signal has gone from an exotic messaging app used by privacy-conscious dissidents to the unofficial whisper network of Washington officialdom. Signal does not use U.S. government encryption and is not hosted on government servers.

Excerpts from a secret group chat between members of US President Donald Trump's administration, seen by editor-in-chief of The Atlantic magazine Jeffrey Goldberg, have shown the disdain for Europe held by some high-ranking US officials.