locale: Cannot set LC_CTYPE to default locale: No such file or directory

Ubuntu 11 errors:

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 the standard locale ("C").
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

After executing the following commands, the error was fixed.

$sudo locale-gen en_US
$sudo dpkg-reconfigure locales