North Korea Expanding it's Nuclear Program

That's right, North Korea has announced that it will expand it's nuclear program. An update from an unidentified North Korean official to the world announced that it is for self defense. When asked why they need this type of self defense they said it was because the U.S. is being hostile towards them and they just want nice peace. North Korea is trying to make nuclear weapons and they will be testing there third one soon. Do they have the technology to actually deliver one of these nukes if they do achieve there goal of making them. Seeing as how last month they did were not able to send there ballistic missile very far, I think not. Should the U.N. intervene? If they are able to get this technology on their own should they be able to do it?