Huge XML-Parsing/converting using R or RDotnet

I have XML file of 780GB (yes yes, indeed, 5GB pcap file which was converted to XML). The name of the XML file is tmp.xml.

I am trying to commit this operation in R-Studio:

require("XML")

xmlfile<<-xmlRoot(xmlParse("tmp.xml"))

When I am trying to do it with R I get errors (memory allocation failure, R session aborted etc). Is there any benefit to use RDotnet instead of the regular R? Is there any way to use R to do this? Do you know another strong tool to convert this huge xml to csv or easier format?

Thank you!