US President Donald Trump and North Korean leader Kim Jong-un will hold a talk in Singapore on June 12. Their agenda is clear: agreeing to dismantle the North’s nuclear programs and setting a road map to carry it out. Their meeting will be a historic watershed for the situation on the Korean Peninsula and Northeast Asia.

The summit will likely produce the outcomes of a big deal apparently in the making between Washington and Pyongyang. The summit results may cover not only the guarantee of the North Korean regime but also the declaration of the end of the Korean War, the signing of a peace treaty, the normalization of US-North Korea relations and economic assistance to the North.

In a joint news conference with South Korean Foreign Minister Kang Kyung-wha in Washington on Friday, US Secretary of State Mike Pompeo offered a glimpse of what US-North Korean relations could look like if they succeed in reaching a nuclear accord. Pompeo said, “If North Korea takes bold action to quickly denuclearize, the United States is prepared to work with North Korea to achieve prosperity on the par with our South Korean friends.”

The US reportedly demands the North’s nuclear programs be dismantled first, while Pyongyang wants phased denuclearizing. How quickly the North is willing to scrap its nuclear programs will be a key barometer of how serious Kim is toward denuclearizing his country.

The US and North Korea share a big picture for denuclearization, but it is too early to be optimistic of the outcomes of their summit. Pyongyang has a track record of making promises to Washington with an intention of cracking the US-Korea alliance, getting as much economic support as possible and making the US pull its troops out of the peninsula.

The North announced that it would close down its nuclear test site at Punggye-ri soon, and yet the announcement is short of convincing the US of its sincerity. The Trump administration must respond to Kim’s overtures carefully.

Trump’s recent expression of “denuclearizing the entire Korean Peninsula” rather than North Korea should be viewed with caution.

Leaders of the North have called for denuclearizing the peninsula to prevent the US from deploying its strategic military assets to the South. If Trump and Kim agree on denuclearizing the peninsula, US strategic assets capable of carrying nuclear weapons may not be deployed any longer during the US-Korea joint military exercises. Particularly worrisome is the possibility that their agreement will exclude the peninsula from the US nuclear umbrella. The South Korean government needs to check on such possibility. Now is time to make all-out efforts together with the US to ensure both a complete dismantling of North Korea’s nuclear programs and a long-term security of the South.

With the US-North Korea summit date and venue set, eyes are on what President Moon Jae-in will do as a mediator between Trump and Kim.

He must mediate to let Trump and Kim know what is on their minds about each other. Moon needs communicate with Kim as often as need be through a hotline. He must try to persuade Kim to have a greater confidence in what the US has promised on condition that he will carry out commitments to denuclearize his country. Moon should do the same with Trump. He must focus on clearing up Trump’s doubt about Kim.

Even if Washington and Pyongyang agreed to denuclearize the peninsula, the agreement cannot become a reality unless both sides have confidence in each other’s promises. If their mutual trust is fragile, their summit will likely end up as a failure. This is where Moon’s mediating role is needed. In addition, Moon should try to narrow differences over the details on how to denuclearize the North.

Cheong Wa Dae should also consider arranging a three-nation summit involving two Koreas and the US after the US-North Korea summit. The sooner, the better. Leaders of the three countries need get together to wrap up denuclearization issues.

It is time to speed up cooperation with the US and contacts with the North to attain its desired outcomes of the summit.