The VA does not allow veteran mortgages for properties outside the United States. The VA does allow purchases in American territories and possessions. These areas include Puerto Rico, Virgin Islands, American Samoa, Guam, and the Northern Mariana Islands. If your proposed purchase is in one of these areas, you should be able to apply in the usual ways, but check with your VA rep for any special requirements or conditions based on the laws which cover lending in those territories.
Regardless of where you purchase a home with a VA loan, the property must meet the basic property requirements set by the VA.