The US will ask you on a card if you are brining in such things, inspect and maybe seize them. They took my sandwich at pre-clearance. You can thank the Bush administration for protecting your farms from diseases that you are bringing in by eating a sandwich, or stocking your freezer. You might to have a label stating that it's pork - beef is what they usually try to stop even though that restriction has been removed.
We live in Japan, thank heaven, and go for food shopping trips every three months. Although we are not altogether sure, what is allowed and what not, we have yet to experience any trouble and hope it stays that way. But thanks for the warning.