White House Chief of Staff John Kelly threatened to quit on March 28, according to sources familiar with the events.

What I’m hearing: Kelly blew up at Trump in an Oval Office meeting that day, and while walking back to his office muttered he was going to quit. Sources said it was not related to the David Shulkin firing that happened the same day.

A senior administration official said that calling it a threat was “probably too strong, it was more venting frustration.” Kelly often says he doesn’t have to be there and didn’t seek the job originally.