I have iPhone5 from Korea and going back to the states

I have iphone5 from korea and i am planning on going to the States.

the iphone is unlocked but my question is would i get LTE on my phone and still covered under apply warranty?

i understand that the phone will work with 3g network but the reason that i got the iphone5 was because of LTE.

would my iphone5 from korea would still cover under warranty in apply store in US?

View the original article here