If you order the iPhone through Apple, Apple will not ship out of the country
whose Apple store was used to order the iPhone - if you order via Apple US,
shipment will have to be to the US. I believe AT&T works the same since
they operate only in the US, but you may wish to contact AT&T to be sure.
Apple has not yet announced a new iPhone or a release date. Remember
that warranty is valid only in country of purchase; so if you buy while out of US,
warranty will not be valid in the US. And LTE needed for US phones will not work
outside of North America and iPhones purchased elsewhere will not work in the US.
TL,DR: short answer is no.