Adding stylesheet to XML breaks formatting

Question

I wanted to add a stylesheet to my xml file. But when I add the xml-stylesheet the whole formatting disappears, and I'm getting pure string of data. How to do it right ?

<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/css" href="sitemap.css"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"&gt;
{% spaceless %}
{% for url in urlset %}
  <url>
    <loc>{{ url.location }}</loc>
    {% if url.lastmod %}<lastmod>{{ url.lastmod|date:"Y-m-d" }}</lastmod>{% endif %}
    {% if url.changefreq %}<changefreq>{{ url.changefreq }}</changefreq>{% endif %}
    {% if url.priority %}<priority>{{ url.priority }}</priority>{% endif %}
   </url>
{% endfor %}
{% endspaceless %}
</urlset>