The transfer concludes a lengthy process in which Icann (Internet Corporation for Assigned Names and Numbers) has been given more of these tasks.
Arizona, Texas, Oklahoma and Nevada have started lawsuits, saying the decision needs Congressional approval.
The handover is scheduled for today.
Icann keeps an eye on the core addressing system of the internet, known as DNS, via a subsidiary called the Internet Assigned Numbers Authority.
DNS translates the names that humans use to navigate the web into the numbers computers use.
