Former New Jersey Governor Chris Christie, once-ally of Donald Trump, has become one of the president's most vocal critics in recent years.

Holt, who has been been the face of “Nightly News” for a decade, will remain at NBC. In a note to staff Monday, he said he would be expanding his work on NBC’s “Dateline,” taking on a full-time role.

Sen. Jack Reed, ranking Democrat on Armed Services Committee, said Trump’s purge of senior Pentagon leaders is a threat to ...