While my experience in this area is limited many countries do accept FAA certificates. Some will issue you a license and others will issue you a Validation. Some of these validations can be quite limited. I was issued one that was limited to a specific aircraft registration. In some cases the country will want you to take a checkride with an examiner and others will accept a certificate of training from a international accepted school (i.e. FSI or Simuflite). Other countries will only issue licenses or validations if yo are sponsored by a domestic company and there are no locals available.
Your best bet is to consider what you are trying to accomplish, pick a country or countries and discuss it with the authorities involved.