You should have a meta tag for the page language (adjust language code as needed):
As far as the URLs go... many sites are converting these to non-escaped variants on save. Magento, for example, treats e, é, and ê as e in the url. Check out Lemonde.fr, french news source. They are just stripping the accents as well.
To adjust for the accents, you would need to transliterate them. First, find the function that is generating the URL. Next, if your system allows has the iconv() function:
If not... then you could go this sort of route:
$table = array(
'Š'=>'S', 'š'=>'s', 'Đ'=>'Dj', 'đ'=>'dj', 'Ž'=>'Z',
'ž'=>'z', 'Č'=>'C', 'č'=>'c', 'Ć'=>'C', 'ć'=>'c',
'À'=>'A', 'Á'=>'A', 'Â'=>'A', 'Ã'=>'A', 'Ä'=>'Ae',
'Å'=>'A', 'Æ'=>'A', 'Ç'=>'C', 'È'=>'E', 'É'=>'E',
'Ê'=>'E', 'Ë'=>'E', 'Ì'=>'I', 'Í'=>'I', 'Î'=>'I',
'Ï'=>'I', 'Ñ'=>'N', 'Ò'=>'O', 'Ó'=>'O', 'Ô'=>'O',
'Õ'=>'O', 'Ö'=>'Oe', 'Ø'=>'O', 'Ù'=>'U', 'Ú'=>'U',
'Û'=>'U', 'Ü'=>'Ue', 'Ý'=>'Y', 'Þ'=>'B', 'ß'=>'ss',
'à'=>'a', 'á'=>'a', 'â'=>'a', 'ã'=>'a', 'ä'=>'ae',
'å'=>'a', 'æ'=>'ae', 'ç'=>'c', 'è'=>'e', 'é'=>'e',
'ê'=>'e', 'ë'=>'e', 'ì'=>'i', 'í'=>'i', 'î'=>'i',
'ï'=>'i', 'ð'=>'o', 'ñ'=>'n', 'ò'=>'o', 'ó'=>'o',
'ô'=>'o', 'õ'=>'o', 'ö'=>'oe', 'ø'=>'o', 'ù'=>'u',
'ú'=>'u', 'û'=>'u', 'ü'=>'ue', 'ý'=>'y', 'ý'=>'y',
'þ'=>'b', 'ÿ'=>'y', 'Ŕ'=>'R', 'ŕ'=>'r', 'Ā'=>'A',
'ā'=>'a', 'Ē'=>'E', 'ē'=>'e', 'Ī'=>'I', 'ī'=>'i',
'Ō'=>'O', 'ō'=>'o', 'Ū'=>'U', 'ū'=>'u', 'œ'=>'oe',
'ß'=>'ss', 'ij'=>'ij'
); $new_url = strtr($old_url, $table);
I'm not sure about Korean handling - perhaps someone else knows how these are being handled?