return HttpResponse(xml, mimetype='application/xml')

from django.contrib.sitemaps.views import sitemap
from django.http import HttpResponse

def generic(request):
    if not request.user.is_superuser: #Чтобы никто не начал злоупотреблять
        return HttpResponse('You not admin')

    sitemaps = {
        'news': NewsItemSitemap,
        'articles': ArticleItemSitemap,
    }

    try:
        xml = sitemap(request, sitemaps)

        f = open(settings.ABSOLUTE_MEDIA + 'sitemap.xml', 'w')
        f.write(xml.rendered_content.encode("utf-8"))
        f.close()
        return HttpResponse('Success')
    except:
        return HttpResponse('Error')