Seoul (CNN) With 20 steps over the military demarcation line at the Korean Demilitarized Zone Sunday, US President Donald Trump made history .

Trump became the first sitting US President to set foot on North Korean soil -- a milestone Trump repeatedly touted in the hours that followed -- and later in a triumphant tweet before departing South Korea on Air Force One, calling the occasion "a great honor."

Those 20 steps were, indeed, a remarkable achievement. The fact that US officials and the notoriously rigid North Korean bureaucracy were able to pull together such a momentous meeting in around 24 hours, after Trump proposed the idea on Twitter, is a testament to the warm personal relationship that has developed over the last year between the two leaders.

It is also highly significant that the two were able to go beyond a simple two-minute handshake previewed earlier by the US President, and speak privately for nearly an hour -- announcing they would form teams with the goal of resuming working level denuclearization talks by mid July.

But as the buzz wears off from a dizzying day of impromptu diplomacy , a far longer and more difficult march lies ahead to achieve the ultimate goal of denuclearization of the Korean Peninsula.

Denuclearization

It was noteworthy that Trump never once mentioned the word denuclearization on Sunday.

If the last year of stalled diplomacy with Pyongyang has proven anything, it's that negotiations over North Korea's prized nuclear arsenal are fraught with complexities and, at times, seemingly insurmountable difficulties.

Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ President Donald Trump meets with North Korean leader Kim Jong Un at the border village of Panmunjom in the Demilitarized Zone, South Korea, on Sunday, June 30. Hide Caption 1 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ The two leaders meet at the demilitarized zone separating the two Koreas, in Panmunjom on Sunday. Hide Caption 2 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ Trump became the first sitting US president to step into North Korea on Sunday, June 30. Hide Caption 3 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ Trump makes history as he steps onto the northern side of the Military Demarcation Line that divides North and South Korea on June 30. Kim looks on as Trump becomes the first sitting US President to walk into South Korea. Hide Caption 4 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ North Korea's leader Kim Jong Un walks to greet US President Donald Trump at the Military Demarcation Line that divides North and South Korea, in the Joint Security Area (JSA) of Panmunjom in the Demilitarized Zone (DMZ) on Sunday, June 30. Hide Caption 5 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ North Korean security agents keep watch south of the Military Demarcation Line that divides North and South Korea, as Trump and Kim meet in the Joint Security Area of Panmunjom in the Demilitarized zone on June 30. Hide Caption 6 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ Kim and Trump shake hands during a meeting on the south side of the Military Demarcation Line that divides North and South Korea on June 30. Hide Caption 7 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ After shaking hands and patting each other's backs while inside North Korean territory, the leaders walked together back across the line into South Korea. Hide Caption 8 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ Kim speaks as he stands with Trump south of the Military Demarcation Line that divides North and South Korea, in the Joint Security Area of Panmunjom in the Demilitarized zone on June 30. Hide Caption 9 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ Trump steps onto the northern side of the Military Demarcation Line that divides North and South Korea, on Sunday, June 30, as Kim looks on. Hide Caption 10 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ White House Senior Advisors Ivanka Trump and Jared Kushner, walk in the border village of Panmunjom in the Korean Demilitarized Zone in South Korea, on Sunday, June 30. Hide Caption 11 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ People at the Seoul Railway Station watch a news program on a TV screen showing Trump and Kim at the border village of Panmunjom on June 30. Hide Caption 12 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ South Korean President Moon Jae-in meets with North Korean leader Kim Jong Un, alongside President Trump at the truce village of Panmunjom in the Korean Demilitarized Zone, on Sunday, June 30. Hide Caption 13 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ Trump meets US service members stationed in South Korea in Osan Air Base, following his meeting with Kim at the Joint Security Area in Panmunjom in the Korean Demilitarized Zone on June 30. Hide Caption 14 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ Trump views North Korea from from Observation Post Ouellette at Camp Bonifas in South Korea on Sunday, June 30. Hide Caption 15 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ Trump talks with South Korean President Moon and views North Korea from Observation Post Ouellette at Camp Bonifas in South Korea. Hide Caption 16 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ Trump and Moon visit an observation post in the Korean Demilitarized Zone separating North and South Korea on Sunday, June 30. Hide Caption 17 of 18 Photos: In Pictures: Historic meeting between Trump and Kim at the DMZ Trump and Moon visit an observation post in the Joint Security Area at Panmunjom in the Demilitarized Zone separating North and South Korea on June 30. Hide Caption 18 of 18

My 19 trips to North Korea have shown me it is a country unique in the world, with a vastly different worldview than anywhere else. Dealing with a country like this requires an equally unique approach.

It may be difficult for outsiders to understand why this isolated Northeast Asian nation clings to an arsenal that has cost it dearly in terms of severe economic sanctions and isolation from much of the global community.

From the North Korean regime's viewpoint, nuclear weapons guarantee their survival as a sovereign state and provide legitimacy for leader Kim Jong Un. Kim spent his first years in power growing his arsenal at breakneck speed, spending much of 2016 and 2017 launching ballistic missiles and testing nuclear weapons at a disturbing pace. North Korea's last nuclear test in September, 2017, was so powerful it triggered a 6.3 magnitude earthquake and literally moved a mountain at it's now-shuttered Punggye-ri nuclear test site.

The world's attention

Kim's defiant and militaristic behavior got the world's attention. North Korean officials in Pyongyang repeatedly told me that Kim's ultimate goal was never to unleash the horrific weapons he created, but to use them to gain leverage and come to the negotiating table from a position of strength.

Arguably, Kim has accomplished that goal in spades. His diplomatic detente with Trump has led to meetings with some of the worlds most powerful leaders, including Chinese President Xi Jinping and Russian President Vladimir Putin. He has also met repeatedly with South Korean President Moon Jae-in, who has staked much of his political capital on keeping diplomacy with the north alive, despite numerous setbacks -- including the collapse of February talks between Trump and Kim in Hanoi, Vietnam, and subsequent bellicose rhetoric and the resumption of short range ballistic missile testing by the North Koreans.

JUST WATCHED Trump shakes hands with Kim Jong Un at the DMZ Replay More Videos ... MUST WATCH Trump shakes hands with Kim Jong Un at the DMZ 01:44

Buys Kim time

Kim has so far been unable to achieve his ultimate goal of relief from crushing sanctions. Sources told me earlier this year he was bewildered by the disappointing outcome of the Hanoi Summit, going so far as to dole out severe punishments for key members of his negotiating team in an effort to save face.

The US has also failed to achieve its ultimate goal of getting North Korea to relinquish any of its nuclear weapons, or even agree upon a definition of denuclearization.

Despite the theatrics of Sundays historic day at the DMZ, those tremendous challenges remain. Both Kim and Trump seem to be banking on their personal relationship as the solution that will help them overcome the huge divide that remains between the US and North Korea.

If anything, Sunday's meeting buys Kim time to prove to skeptics inside his country that he is capable of striking a deal with the US, despite the breakdown of talks in Hanoi.

Working level negotiations have proven an utter failure thus far. Barring a significant shift in either the US or North Korean positions, there is a little reason to be optimistic about the long-term results of Sunday's triumphant 20 steps at the DMZ.