On March 7, 2013, North Korea threatened to cancel the 1954 Cease Fire that created a state of peace between north and South Korea. This comes in light of the UN Security Council draft of new restrictions.
North Korea tested a missile on Feb 12, which breached restrictions that were placed on North Korea. A spokesman for Pyongyang's foreign ministry said that the North will "preemptive nuclear attack to destroy the strongholds of the aggressors," this comes in light of another security meeting to restrict North Korea's capabilities even more.
Analysts are calling North Korea's threat a lot of "saber rattling" but the Pentagon is taking the threat seriously. Right now we know that North Korea has the capabilities to shoot a missile off with 6200 mile radius. This would make the entire Pacific Coast and Hawaii prone to a nuclear attack if it were to happen.
The US said officially that "we are perfectly capable of preventing a ballistics attack from North Korea."