The US-North Korea denuclearization talks that have come to a stalemate should raise two key questions. The first question is about whether the North intends to fulfill its promise to do away with its nuclear and missile menace on its own, and the second one is about what role South Korean President Moon Jae-in could play to resolve the problem.

It is not the first time that the first question has been raised since North Korean leader Kim Jong-un offered his denuclearization commitment in his meetings with Moon and US President Donald Trump. But skepticism has risen further in the wake of Trump’s cancellation of Secretary of State Mike Pompeo’s visit to Pyongyang.

In a sense, the cancellation once again highlighted the unpredictability on the part of both Trump and Kim. But the bigger problem is that it may herald a long hiatus in the US-North talks to denuclearize the North.

In fact, the US and the North have made little progress in their denuclearization talks since Trump and Kim held their historic meeting in Singapore in June. The meeting came after Kim made the same denuclearization commitment in a meeting with Moon, the first inter-Korean summit in 11 years in April.

US National Security Adviser John Bolton said that his South Korean counterpart, Chung Eui-yong, told him that Kim pledged to Moon in their April meeting that the North would complete its denuclearization work within a year.

As things stand, there has been no signs of that happening. The North has only made some superficial, cosmetic actions, including the destruction of a nuclear test site and a partial dismantlement of a missile testing site. In another peace gesture, the North returned 55 sets of remains of American soldiers who perished during the Korean War.

But satellite images and intelligence reports have shown the North was continuing its nuclear and missile-related activities, which raised doubts about its denuclearization commitment. Besides, the North has refused the US demand to provide an inventory of its nuclear arsenal and facilities and a road map for a final, fully verified denuclearization.

Instead, the North is pushing the US and South Korea to declare an end to the Korean War first, which the North had insisted should lead to signing of a permanent peace treaty with the US. This longstanding demand is key part of the North Korean strategy to guarantee its security by precluding the US from military strikes or other hostile acts.

All this means that the North is engaged in its usual tactic: It offers some peace gestures, and demands generous rewards, while leaving things open for it to go back to square one at any time and resume its brinksmanship. The international community, not least the US and South Korea, needs to bear this in mind and devise ways to keep the denuclearization work on the right path.

It is against this backdrop that President Moon’s planned visit to Pyongyang next month is important. There is both skepticism and optimism about the possibility that the third inter-Korean summit could pave the way for a breakthrough to the US-NK deadlock.

Optimism is based on the fact that Moon brokered the historic meeting between Trump and Kim. But there are enough grounds for skepticism too.

Most of all, the North -- while working with the South on some reconciliation programs -- avoids discussing denuclearization with the Seoul government. This causes concerns that the increasing inter-Korean engagements could only benefit the North economically and run the risk of causing cracks in the international sanctions on the Pyongyang government.

In Pyongyang, Moon will face the challenge of further boosting inter-Korean cooperation programs without creating loopholes in the UN- and US-led international sanctions. His government has already faced criticism for some South Korean businesses’ imports of North Korean coal disguised as products coal from Russia and the plan to open a joint liaison office in a North Korean city regarding possible violations of the sanctions against the North.

After all, the overall direction of the North Korean nuclear issue will be determined by whether Kim has a genuine intention to denuclearize his country. Moon’s foremost job in Pyongyang is to find out what Kim has on his mind.