From the interview with Fauci linked above:

Q: What happens before each press conference? What do you do as a group?

A: We're in the task force. We sit down for an hour and a half, go over all the issues on the agenda. And then we proceed from there to an ante room right in front of the Oval Office to talk about what are going to be the messages, what are the kind of things we're going to want to emphasize? Then we go in to see the president, we present [our consensus] to him and somebody writes a speech. Then he gets up and ad libs on his speech. And then we're up there to try and answer questions.