Basically, the North don't have genuine ballistic capability at the moment, but they are a nuclear state which is something to be very concerned about. The real issue is with China though, who publically condemn their testing and agree with the UN sanctions yet continue to trade goods and send aid to DPRK.
And while China is sending aid, the West has imposed sanctions, in the hope that it will topple the regime. Which hasn´t worked for the last 50 years and which has allowed the north Korean ´supreme leaders´ to stifle dissenting opinions in the country by pointing to the ´obviously evil, envious and imperialist west´.
Lessening the sanctions would take away the stick they use to beat the people with and alleviate the grave hunger issues in the country.