Debian 9 Stretch で locale の変更

$ localectl
   System Locale: n/a
       VC Keymap: n/a
      X11 Layout: us
       X11 Model: pc105
$ localectl list-locales
C.UTF-8
en_US.utf8
$ sudo localectl set-locale LANG=en_US.UTF-8
$ localectl
   System Locale: LANG=en_US.UTF-8
       VC Keymap: n/a
      X11 Layout: us
       X11 Model: pc105