Based on its specifications, it should work, as long as it's unlocked. Keep in mind that bringing a phone from another carrier might have its issues even if it technically works, some features might not work or not work properly. In some cases they're slower too as they may not be able to connect to LTE.
Did a post have a solution that worked for you? Help other people find solutions faster by marking posts that helped you as an "Accepted Solution". Learn about accepted solutions: Learn More.
*I am an AT&T employee and the postings on this site are my own and don't necessarily represent AT&T's position, strategies or opinions.
Also, before you buy, be aware that Apple's warranty is valid only in the country in which the phone is purchased. If you take it to another country, you'll have no warranty without returning it to where you bought it (in person...no overseas shipments accepted).