The Nork Kims' obsession with nuclear weapons is not new and they have broken several agreements to this point

Weekly Standard:

Since Donald Trump took office, the growth of North Korea’s nuclear arsenal and the increasing capability and diversity of its ballistic missile force have made that country the most urgent threat to U.S. national security. Observers as diverse as Mark Bowden in the Atlantic, Michael Auslin of the Hoover Institution, and former White House chief strategist Steve Bannon agree that all military options available to the president are bad. How exactly did we get to this point? What policy decisions led to an emerging intercontinental ballistic missile capability and a nuclear arsenal that could rival that of the U.K. by the middle of the next decade? How did we end up with a North Korean leader seemingly more willing to run enormous risks than his father or grandfather? The answer demonstrates once again the venerable adage that “the road to hell is paved with good intentions.” One of the few national figures who consistently raised alarms about U.S policy towards North Korea was former vice president Dick Cheney, and he has proven prescient. The United States now faces the real prospect of a war that Secretary of Defense James Mattis says would be “catastrophic.” This story should be studied carefully before it repeats itself—say, in Iran.

Kim Il-sung manifested an interest in obtaining nuclear weapons almost as soon as he founded the North Korean ruling dynasty, in the early 1950s. His Soviet patrons were not prepared to oblige but did help to build a nuclear research reactor in Yongbyon that could provide a source of plutonium. His unrequited urge for nuclear weapons led Kim to approach Mao Zedong after the successful Chinese nuclear test in 1964, but he was again turned down. Ultimately Moscow, wanting to keep the number of nuclear-weapon states low, persuaded Pyongyang to sign the Nuclear Nonproliferation Treaty in 1985. But North Korea procrastinated about signing the mandatory safeguards agreement to give the International Atomic Energy Agency access to the Yongbyon reactor and other nuclear facilities while quickly initiating a clandestine program to reprocess fissile material for its nuclear arsenal. The loss of its superpower patron after the collapse of the Soviet Union made nuclear weapons a matter of some urgency for the Kim dynasty. Thus began a pattern of serial prevarication and the use of “arms-control” negotiations as a cover for covert activity.

One pretext the North used to avoid concluding a safeguards agreement was the presence of U.S. theater nuclear weapons in South Korea. As the Cold War wound down, President George H.W. Bush working with his Secretary of Defense Dick Cheney announced his Presidential Nuclear Initiative to withdraw all sea- and land-based tactical nuclear weapons from their locations, including those forward-deployed to the Republic of Korea. Soviet president Mikhail Gorbachev in the waning months of his tenure agreed to do likewise. This prompted South Korean president Roh Tae-woo to renounce any intention to produce, possess, store, or use nuclear weapons on ROK territory. Stripped of any remaining rationale for denying the IAEA access to its facilities, North Korea agreed in December 1991 to a Joint Declaration calling for the denuclearization of the Korean peninsula. The two sides agreed not to “test, manufacture, produce, receive, possess, store, deploy or use nuclear weapons” or “possess nuclear reprocessing and uranium enrichment facilities.” They agreed in principle to an inspections regime to verify the joint declaration. The North signed an IAEA safeguards agreement in January 1992 and provided its first statement to the agency a few months later.

The IAEA quickly realized that there were discrepancies in the documentation Pyongyang provided. The agency sought clarifications on the amount of plutonium North Korea had secretly reprocessed and, as officials became more suspicious about the country’s claims, asked for special inspections. The North refused and threatened to withdraw from the NPT. Fearful of the impact a withdrawal might have on the treaty, Bill Clinton’s administration began almost two years of intensive crisis diplomacy that culminated in the Agreed Framework.
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There is more.

Those seeking a diplomatic solution to this problem ignore the most important point.  The North Korean's word is no good. 

They may have a brief pause in their overt objectives, but they keep working on getting nuclear weapons. Every deal they have made has been broken. 

That is why we are where we are today with them producing hydrogen bombs and ICBMs. 

The stark choice is not to accept nuclear weapons in a country where deterrence will not work.  It is whether to destroy North Korea's program now or do it when they have the capacity to wipe out US cities and wipe out the US electric grid.