Justin Bieber -- Usher in Panama for Save Justin Summit

Usher has high-tailed it down to Panama to talk some sense into Justin Bieber ... TMZ has learned.

Justin and his mentor posed for pics with a woman who appears to be a Panamanian Belieber (they really are everywhere).

Sources tell us Usher flew to Panama for a serious come-to-jesus with JB on the heels of his arrest in Miami.

We're told Justin's manager Scooter Braun, and Justin's childhood friend Ryan Butler, are also there for the sit-down. Scooter got roped in for a pic with a Belieber at the resort where they're all staying.

We haven't heard this word used, but this meeting has all the earmarks of an intervention.

Worth noting ... even the fan who posted the Usher pic acknowledges the kid's hit rough times, describing him as the youth idol who some love and many others hate.