$ sudo locale-gen "en_US.UTF-8"
Generating locales...
en_US.UTF-8... done
Generation complete.
$ sudo dpkg-reconfigure locales
Generating locales...
en_US.UTF-8... up-to-date
Generation complete.
$ sudo locale-gen "en_US.UTF-8"
Generating locales...
en_US.UTF-8... done
Generation complete.
$ sudo dpkg-reconfigure locales
Generating locales...
en_US.UTF-8... up-to-date
Generation complete.