So 40 minutes from now at least?
The meeting already happened. It's not a public briefing ffs, it's the briefing on the events of today. We're to standby and see what POTUS says to us later. Whenever a major security event happens, it goes through the president, and then to us. That's why the briefing was over an hour ago.
I'd assume it's Vietnam time, since he's in Vietnam right now. Vietnam time at posting this reply is 4:12AM
Vietnam is basically China-lite at this point anyways.