Who cares if North Korea has nuclear weapons,if South Korea has a problem with it let them have nuclear weapons too.Who are we to decide what North Korea can and can't have it is their country not ours.Let them govern themselves before we do anything.So yes the sanctions need to be lifted.
North Korea has not come anywhere close to proving that they can be trusted, if anything, they have been doing exactly the opposite of that. They should continue to have nuclear sanctions until they can prove to the world that they are responsible and not governed by a bunch of nuts.
I do not think that now is the time for the UN to be backing down from North Korea in wake of North Korea breaking it's already in place sanctions and forging ahead with a nuclear program. The UN must stand firm with sanctions to show North Korea that they are not in control.
North Korea is a dangerous country, ruled by a dictator in thrall to his military and capable of causes real devastation in Asia or further if allowed to acquire nuclear weapons. Peaceful existence with South Korea would be impossible if their was the constant threat of nuclear strikes from a hostile neighbor. Additionally, even if North Korea's government could be trusted, they are in danger of being overthrown by the military.