I think Pentagon Spokesman Geoff Morrell had the perfect response to that statement..
“I don’t even know how you respond to such silliness. Wipe the United States off the map? For what and with what?”
Nice! I’m glad someone stood up and said NK is writing checks they can’t cash. If you want to dance, Big Daddy Kim, you better bring it with both barrels.
And a step ladder……shorty.
Oh, and better find some better toys, because one 6 kiloton explosion is going to do much except piss us off.