Earlier quoted context omitted.
Take care of how?
Probably doing similar things to what's been done with Russia, more sanctions, more sanctions against supporting nations etc. They're soon to test a nuclear weapon and already play fun games testing missiles and having them land just off the coast of Japan. Not going to be fun once those things are nuclear missiles and en route to Tokyo.
Sanctions against Russia aren't uniquely effective in a way that sanctions against NK aren't. It's just that the threat of having your economy look like North Korea's is pretty dire.