Digitalocean debian droplet issue with locale

The issue message when installing something with apt-get:
(maybe is the same for ubuntu, son of debian)

Can't set locale; make sure $LC_* and $LANG are correct!
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LC_CTYPE = "UTF-8",
LANG = "en_US.UTF-8"
    are supported and installed on your system.
perl: warning: Falling back to a fallback locale ("en_US.UTF-8").
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory

SOLUTION:

edit /etc/default/locale with your locale settings, for example:

LANGUAGE=es_MX.UTF-8

LANG=es_MX.UTF-8

LC_ALL=es_MX.UTF-8

LC_TYPE=es_MX.UTF-8

save and reboot.