How to copy file using Rest API and javascript in Sharepoint 2013 between site and subsite

I need to copy file between document libraries. Library A is located in one site and Library B is located in subsite. I know how to copy file between libraries on the same level but the problem is with copying between different level.

The code I use to copy file between libraries on the same level.

 $.ajax({
     url : "http://xxx/PWA/_api/web/folders/GetByUrl('/PWA/CopyFromLibrary')/Files/getbyurl('Import.csv')/copyTo(strNewUrl = '/PWA/TargetLibrary/Import.csv',bOverWrite = true)",

method: 'POST',
    headers: {
        "Accept": "application/json; odata=verbose",
        "X-RequestDigest":  $("#__REQUESTDIGEST").val()
    },
    success: function () {
        alert("Success! Your file was copied properly");
    },
    error: function () {
        alert("Problem with copying");
    }
    });

For different level I use just another target URL:

url : "http://xxx/PWA/_api/web/folders/GetByUrl('/PWA/CopyFromLibrary')/Files/getbyurl('Import.csv')/copyTo(strNewUrl = '/PWA/Subsite/TargetLibrary/Import.csv',bOverWrite = true)",

And it doesn't work. How to work around this problem?