How to set/delete cross domain cookie?

I need to delete cookie on another domain (controlled by me) without reloading page and opening new window. I'm trying:

        var XHR = window.XDomainRequest || window.XMLHttpRequest
        var xhr = new XHR();
        var url = another_domain_url_which_removes_cookie;
        xhr.open('GET', url, true);
        xhr.send()

but still after hitting target url cookie remains. If I change code to:

        var url = another_domain_url_which_removes_cookie;
        window.open(url)

it all works OK. Server code which removes cookie is the following (python/werkzeug):

response = Response({}, mimetype='application/json')
response.delete_cookie('cookie_name')

Do you guys have any idea how to make it work if this possible?

Solution

Try posting your request in a hidden iframe of your doc...

Html

<iframe style="display:none;" id="myiframe"/>

$("#myiframe").src(url);