Waltz was on television as late as Thursday morning, promoting the administration’s agreement with Kyiv that would allow the U.S. to access Ukraine’s critical minerals and other natural resources.

Waltz was at the center of the Signal chat controversy, in which a journalist was accidentally included in a discussion of sensitive military information.

President Donald Trump is replacing his National Security Adviser, Mike Waltz, and nominating him to be Ambassador to the United Nations, he announced Thursday, marking the first major personnel shake-up of Trump’s second term.