While not related to XML sitemaps, associating domains with a geographic target, also called geotargeting, is often brought up together with XML sitemaps as both things are accessed through Google Webmaster Tools.
Generally, search engines like Google and Yahoo associate domains with a geographic target based on:
- Domain name extension. Examples: .com is neutral, .co.uk is UK and .dk is Denmark.
- IP Address of webhost server and IP Address of DNS nameservers.
- Language used in pages found throughout the domain. <html lang="en">.
- From which countries and domains backlinks are coming from.
When users enter search queries into search engine like Google and Yahoo, the IP address of the user is taken into account when
providing search results. The idea is the search results become more relevant and targeted to the user.
First you have to find the relevant options in
Google Webmaster Tools.
You can only force change geographic target for domain without a country specific domain extension, also called
TLD.
It does not matter if you have had an English language based website for 10 years, if it is a
.dk domain,
Google forces domain geographic targeting to the country/region Denmark. However, if you have a language and country neutral domain
TLD,
you can set the geotargeting of the domain.
Help Forums
To see all the options available, you will have to 
