Let's see... well, a quick google gives us http://www.ala.org/alsc/newbery_terms.html, which is the page of rules, and http://www.ala.org/alsc/nmedal.html, which is the history of the award.
On the rule pages we learn that "The Award is restricted to authors who are citizens or residents of the United States."
(The National Book Award is only for US citizens. And I remember Frank McConnell grumbling magnificently that he would have got Sandman a Pulitzer the year he was a Pulitzer fiction judge, if only I'd had the courtesy to be a US Citizen. I doubt it, but it was a nice thing of him to have said.)
And to try to make up for the Dsicwrold typo in the films section, here's an article on Terry Pratchett from today's Guardian.