In a typical Amazon Web Services(AWS) Environment, Amazon Machine Images (AMIs) are strictly available in a certain region only. These AMIs cannot be moved from one region to another. Though the AMIs are shared within different Availability Zones of the same region.
For this purpose, you can use a third party tool called as CloudyScripts.
CloudyScripts is a collection of tools to help you programming Infrastructure Clouds.
The web-based tool is self explanatory and regularly updated. In case you find any bug, do not hesitate to email the owners right away.