SEOUL, South Korea (AP) — After a summit high on theatrics, emotional displays of Korean reconciliation and some important but familiar sounding plans to boost bilateral relations, North Korean leader Kim Jong Un has safely returned to Pyongyang and South Korean President Moon Jae-in to his official residence in Seoul.

But is buyer's remorse about to set in?

Despite its feel-good emphasis on relationship-building, the first inter-Korean summit in more than a decade left a lot of question marks around the biggest and most contentious agenda item of them all: denuclearization. And that puts the ball squarely in the court of President Donald Trump, whose much anticipated sit-down with Kim is expected to be just weeks away.

For Moon and Kim, that was probably a feature, not a bug. They were both looking to make a show of Korean unity. But it could complicate matters for Trump, who has raised expectations of a deal with Kim to abandon his nuclear weapons much higher. In the long run, that could complicate things for everyone involved.

For sure, Friday's day-long summit inside the Demilitarized Zone that divides the Koreas was a major step forward for diplomacy and could set a more solid foundation for future, more substantive talks. Starting off with a meeting that establishes goodwill and personal relationships at the highest level is a smart move, particularly when there is so much animosity in the air.

Moon also proved he really knows how to put on a show — and Kim revealed his skill at playing along for the cameras.

The two seemed almost like old pals, hugging and holding hands, sitting off to themselves on a footbridge in the Demilitarized Zone for a private "chat" that lasted nearly a half hour. As they exchanged their first handshake, Moon motioned for Kim to cross the concrete slab that marks the division of the nation — a hugely symbolic, albeit highly choreographed, moment.

Kim then went off script, according to South Korean officials, and motioned for Moon to take a step back and join him in the North. The seemingly impromptu dance seemed to encapsulate the reality, some might say absurdity, of their nation's division along the 38th parallel, a decision made not by Koreans themselves but by a U.S. military trying to counter Soviet expansion after Japan's defeat in World War II.

The summit follows meetings between Kim's father, Kim Jong Il, with South Korean presidents in 2007 and 2000. Each produced similar sounding vows to reduce tensions, replace the current armistice that ended the fighting in the 1950-53 Korean War and expand cross-border engagement.

One difference from Friday's summit was the pledge by Kim and Moon to officially declare an end to the conflict this year.

They also announced a series of engagement measures. They will set up a liaison office in the North Korean city of Kaesong, which is near the border and is the site of a now shuttered industrial complex that had for years been the biggest joint project between the two countries. Moon will visit Pyongyang in the fall, high-level military talks will be held next month and reunions will be arranged for families separated by the war.

All of these measures are significant.

They underscore a real policy shift in the South away from the hard-line approach taken by its previous president, Park Geun-hye. Moon clearly is interested in pursuing a less volatile relationship with the North on several fronts and appears unwilling to put all of that on hold until Kim agrees to some sort of quick and complete denuclearization.

He also seemed to steer well away from human rights issues, which have been all but forgotten in the shadow of the North's nuclear program. That's a bit of a blow to Tokyo, which has been largely sidelined lately and hoping that Moon would bring up the matter of what happened to Japanese abducted by the North in the 1970s and '80s.

More importantly, the softer approach, while helping many South Koreans breathe easier after the exceptionally high tensions of last year, puts Seoul and Washington on conflicting paths.

Trump welcomed the talks on Twitter.

But the messaging from the White House remains ambiguous. Trump has suggested Pyongyang must demonstrate a commitment to denuclearization before his policy of maximum pressure on the North can change.

Moon, on the other hand, seems willing for the most part to kick the nuclear issue down the road. He signed off on a pledge with Kim to seek the complete denuclearization of the Korean Peninsula — a phrase that sounds good on the surface but has very little practical meaning without the inclusion of specific measures, time frames and even a definition of exactly what the word "denuclearization" means.

This is where the obligatory mention of the devil being in the details comes in.

The United States hasn't kept nuclear weapons on the Korean Peninsula since the early 1990s. But for Pyongyang, denuclearization has generally been taken to mean the removal of South Korea from Washington's "nuclear umbrella." That would mean Washington must somehow assure Kim that his country is safe from a nuclear attack — and that's a very complicated thing to do.

Maybe that will all become clear when Kim and Trump meet.

But so far, neither has offered any realistic, detailed proposals.

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Talmadge has been the AP's Pyongyang bureau chief since 2012. Follow him on Instagram and Twitter: @EricTalmadge