The planned visit to North Korea of President Moon Jae-in’s special envoy raises both expectations and concerns. What’s certain is that how it goes will have many repercussions.

Taking the positive aspects first, the envoy’s visit -- which comes at a time the North and the US are deadlocked over denuclearization -- may finalize details of a third meeting between Moon and North Korean leader Kim Jong-un scheduled for this month. If Moon, who brokered the historic Singapore summit between US President Donald Trump and Kim in June, meets Kim in Pyongyang as planned, perhaps he could again play a mediating role between the two leaders.

South Korean officials did not refrain from saying that there had been some undisclosed contacts between the two Koreas over the envoy’s visit. This raises hopes that the two sides would at least be able to agree on the dates of the Pyongyang meeting.

A successful meeting between Moon and Kim could help the US and the North find a breakthrough to the stalemate over the US demand for the North’s denuclearization and the North’s demand for declaring an end to the Korean War as part of Washington’s safety guarantee of the Pyongyang regime.

The envoy’s visit does not come only with positive expectations. In some sense, the latest developments show that inter-Korean relations are not so good.

For instance, a special envoy would have been unnecessary under normal circumstances, as the dates for Moon’s Pyongyang visit could be set in another round of high-level talks at the truce village of Panmunjom. The agreement to hold a third Moon-Kim meeting in Pyongyang in September was made in a Panmunjom high-level meeting last month, although their failure to fix dates generated some speculation.

Now there may be some reasons that necessitated indirect communication between Moon and Kim. A Cheong Wa Dae spokesman said Moon decided to send an envoy Wednesday because he believed there should be “no more delay” if the two Koreas were to hold a summit this month. This also implies that the North – perhaps in consideration of its relations with the US -- may not be keen on a meeting with Moon.

Indeed, the North has been stiffening its stance toward the US, which responded by canceling a planned visit to Pyongyang by Secretary of State Mike Pompeo.

Then US Secretary of Defense James Mattis said the US may resume joint military exercises with South Korea, some of which were called off after the Trump-Kim meeting in Singapore. These latest developments raised the specter of the two sides going back to square one.

This threatens Moon’s hope that based on a successful meeting with Kim in Pyongyang, he will be able to mediate another meeting between Trump and Kim, and bring them together for a joint declaration of the end to the Korean War at the UN General Assembly in late September.

Moon’s envoy will go to Pyongyang at a time when the denuclearization deadlock between the US and the North is hampering inter-Korean cooperation programs as well.

The Moon government had to delay opening a joint liaison office in the North Korean city of Kaesong and work to connect inter-Korean railways due to opposition from the US side, citing possible violations of the UN-led sanctions against Pyongyang.

That is an embarrassment for Moon, who maintained that improvement of inter-Korean relations need not necessarily go in parallel with progress of US-North relations.

All in all, what Moon’s envoy hears from North Korean leadership this week would give clues as to what its intention is regarding denuclearization and relations with the US and the South.

What should not be forgotten is that denuclearization should come ahead of everything in engaging the North, and the international community will never allow the North to hold on to its nuclear arsenal and missiles. The most important mission of the envoy is to unequivocally deliver this message to the North Korean leadership.