The White House said Monday it has concluded its review into how a journalist was added to a Signal message group chat, as high-ranking officials discussed military strikes in Yemen, calling the case "closed.

When Donald Trump selected Mike Waltz to serve as national security adviser, the choice was widely seen as win-win: A combat veteran with four Bronze Stars would bring his judgment to the White House and his deep-red Florida House district was safe in Republican hands.

The Trump administration sought to put the scandal over its use of the Signal messaging app behind it on Monday, calling it case closed, even as the breach provoked bipartisan criticism and opened up divisions inside the White House.