US President Donald Trump and North Korean leader Kim Jong-un are set to hold their second summit in earnest today.

The key question is whether Kim will offer meaningful steps to denuclearize his country.

Above all, Trump must not give up too much in return for insubstantial denuclearization measures from Kim.

What Trump must avoid at all costs is a deal that effectively recognizes the North as a nuclear state in return for the promise to freeze its nuclear program. That would be a worst-case scenario for South Korea.

For now, the chances of the North scrapping its entire nuclear program are slim. The North has so far rejected demands it disclose an inventory of its nuclear arsenal and subject that inventory to outside verification. Instead it has merely offered to destroy its nuclear facilities at Yongbyon, among other locations, in exchange for considerable sanctions relief -- even before entering into a second summit.

The biggest reason Kim has come to the table with Trump for the second time is that international sanctions are choking his regime and his country’s economy. If the US eases sanctions while North Korea is still not yet completely denuclearized -- for example, by agreeing to reopen the Kaesong industrial park and resume the Kumgangsan tour program, both sources of hard currency for the North -- Pyongyang will respond passively to future offers to negotiate.

There are concerns the US may settle for just such a deal: incomplete denuclearization in exchange for a certain degree of sanctions relief.

In private discussions with Korea experts, US Secretary of State Mike Pompeo has conceded that it would be lucky if the North agreed even to 60 percent of what the US has demanded.

For his part, this is what Trump said during a meeting with US governors at the White House on Sunday: “I just don’t want testing. As long as there’s no testing, we’re happy.”

Those remarks give the impression that Washington might be ready to set up liaison offices, declare an end to the Korean War and allow the resumption of the tour program and operations at the industrial park if the North promises only to refrain from nuclear and missile testing.

At the slightest slip, this could lead to the effective recognition of North Korea as a nuclear state and to a scenario where the South pays the economic price for the deal -- perpetually living under the constant nuclear threat from the North. The Trump-Kim summit must not go in such a direction.

North Korea’s proposals will be meaningful if they include a concrete road map to the dismantlement of its nuclear program, including its existing arsenal, not to mention the Yongbyon nuclear facilities. The North wants sanctions relief in exchange for steps toward denuclearization, but it should not get what it wants if those steps fall short of expectations.

However, President Moon Jae-in has continued to express his willingness to start inter-Korean economic projects to the benefit of the North -- and ultimately the Kim regime -- without a word about denuclearization.

Showing great optimism for the US-North Korea summit, Moon recently iterated the following vision: “Standing at the center of history, not the periphery, we will take the lead in preparing for a new Korean Peninsula regime -- one that is moving from war and confrontation toward peace and harmony and from factionalism and ideology toward economic prosperity.”

However, he did not demand the North dismantle its nuclear program.

“If the North Korean economy opens up, neighboring countries, international organizations and global capital will join in its development,” he said. “In this process, we should not lose the initiative either.”

Few would oppose the South taking the initiative in opening up the North Korean economy. The communist state must open its doors, not only economically but also socially and culturally.

Someday, both Koreas may be able to establish the new regime that Moon envisions, but not just yet. Now is the time to concentrate on denuclearization.

Sanctions relief, and particularly economic projects, must be preceded by the complete denuclearization of the North. Washington and Seoul must proceed in this order. Kim must know that this order cannot be reversed, and he must offer meaningful steps toward denuclearization. He cannot gain both an economic revival and the right to have nuclear arms.