I recommend you buy a small back-packers butane stove when you get to USA. You can get sealed pouches of food and heat them up anywhere. These are good and not expensive. I have used some by this company:
http://shop.tastybite.com/Entres/c/T...FSU6QgodCFEAtw
and I believe they and other brands are available at larger supermarkets, Whole Foods market, World Market, etc.

Jon