US President Donald Trump and North Korean leader Kim Jong-un cut short their two-day summit in Hanoi on Thursday without reaching a deal on the North’s denuclearization. They left the summit venue after canceling their working lunch and a deal-signing ceremony.

During a post-summit press conference, Trump said he had to “walk away” from the talks with no deal, as Kim had demanded the lifting of all sanctions on Pyongyang while suggesting denuclearization steps that fell short of what the US wanted.

Trump said Pyongyang “had to give up more.” North Korea appears to have sought as many concessions as possible from the US in exchange for decommissioning its Yongbyon nuclear complex. It now finds itself in the position of having to respond to US demands that it should do more in order for sanctions relief to be considered.

Trump was right to leave the summit with no deal rather than a bad deal. His decision puts to rest concerns that he might settle on a deal with Kim that would give diplomatic rewards and partial sanctions relief to the Kim regime in return for limited measures on dismantling its nuclear arsenal.

The Hanoi meeting was meant to put flesh on the scant achievements from the first summit between Trump and Kim in Singapore last June. The Singapore summit produced a vaguely worded accord, with both leaders agreeing to work toward the “complete denuclearization of the Korean Peninsula” without specifying what this would entail.

The possibility of significant progress being made this time around was not high. Trump appeared to be managing expectations ahead of the summit, saying he was in “no rush” to push for denuclearization.

He has now put himself in what seems to be an advantageous position of waiting for the North’s response to US demands for additional steps toward dismantling its nuclear and long-range missile arsenals.

At the press conference joined by US Secretary of State Mike Pompeo, Trump said he has not committed yet to another summit with Kim, adding that the “next meeting might be soon, might not be for long time.”

Meanwhile, negotiating teams from the two sides are expected to resume talks in a bid to set the stage for a possible third summit between their leaders.

With a comprehensive deal on the North’s complete denuclearization pushed back again, it is uncertain how ready the Kim regime is to relinquish its nuclear arsenal, which it sees as essential for its survival.

As intelligence officials and experts have pointed out, Kim may have no serious intention of completely giving up his nuclear weapons and production facilities. This view calls into question the efficacy of diplomatic efforts to denuclearize the North.

Although the Hanoi summit was shortened, Trump still made clear his commitment to diplomacy with Kim. But he declined to comment on whether sanctions could be lifted only after full denuclearization.

Any significant lifting of sanctions should come after establishing the framework for dismantling the North’s nuclear arsenal. A specific road map with a time limit should be worked out to ensure Pyongyang remains committed to complete, verifiable and irreversible denuclearization.

In his call to South Korean President Moon Jae-in from his plane en route to Washington, Trump asked him to “actively” facilitate future dialogue with the North Korean leader.

While expressing disappointment over the failure to reach an agreement in the Hanoi summit, Trump reaffirmed his determination to resolve the nuclear issue through continuous dialogue with Pyongyang, a spokesman for Moon said.

In this regard, South Korea should assume a more active role in the process of denuclearizing the North, not just as a mediator between Washington and Pyongyang.

President Moon’s administration is more than ready to resume economic cooperation with North Korea, if the partial lifting of sanctions on the Kim regime enables it to do so, while leaving the task of resolving the nuclear issue to the US.

Seoul needs to be more involved in future negotiations between the US and the North, and eventual talks on achieving permanent peace on the peninsula, which could also involve China, Japan and Russia.

It must also guard against Pyongyang’s attempt to use a possible peace declaration with Washington as a way to eventually engineer the drawdown of US forces in South Korea and lead the two Koreas to the goal of reunification on its terms.

There had been speculation that a joint document that was to be signed by Trump and Kim after the summit had included a declaration to end the 1950-53 Korean War, which was brought to a halt by a truce not a peace treaty.

While trying to carve out a deal with the US to reduce, not eliminate, the North’s nuclear arsenal, Kim is pushing to lift his country from poverty -- a task that he may think is essential to enable him to remain in power for decades to come.

As he seeks for his country’s future path, he may find that Vietnam’s success story over the past three decades could be a useful model to follow. Therefore, his two-day official visit to Vietnam following the summit carries significance.

Kim was quoted recently by a former US intelligence official as telling Pompeo on his visit to Pyongyang last year that he did not want his children to “carry the nuclear weapon on their backs to live through their entire life.” This could be interpreted as suggesting he intends to retain North Korea’s nuclear capabilities at least for his generation, which would make it hard to remove sanctions on the impoverished North.

If he chooses to return home to Pyongyang on the train that took him to Hanoi, traveling about 4,000 kilometers over two days, he may have time to think again about what choice would best serve the interests of his children.