function block_visitors() { $blocked_countries = array('US'); $ip = $_SERVER['REMOTE_ADDR']; $api_url = "http://www.geoplugin.net/json.gp?ip=".$ip; $visitor_data = json_decode(file_get_contents($api_url), true); $visitor_country = $visitor_data['geoplugin_countryCode']; if (in_array($visitor_country, $blocked_countries)) { wp_die('Sorry, access to this website is blocked from your country.'); } } add_action('wp', 'block_visitors');