said 10 months ago:
By default the tags are only available for posts.
You could use the WordPress SEO plugin by Yoast http://wordpress.org/extend/plugins/wordpress-seo/ .
Here you have an extra field for tags. However most search engines don’t use these tags anymore, especially Google does not use meta tags for ranking.
However, with this plugin you can see on the analysis tab how your page is doing with the focus keyword for that page. This is a great feature from this plugin that you can use for pages and posts.