As Hee-jun said, the North agreed to shut down a key missile engine testing site, and there could be more closures ahead.
Our Cha Sang-mi asked several experts... about for the significance of this measure.
The denuclearization talks are back on the track.
At Wednesday's joint press conference, President Moon said the two sides have agreed on the next steps.
President Moon called the North's promise to permanently close the Dongchang-ri engine testing and missile launch site "a very meaningful outcome" and said the permanent denuclearization of the Korean Peninsula will be achieved before long.
The Yeongbyeon complex is the North's most important nuclear facility, so getting rid of it would be a meaningful step indeed.
Among those keeping close tabs on these developments is Professor Song Se-ryun, who says that progress on denuclearization could open the door to another summit between North Korea and the U.S.
But he also said President Moon might have expected something more out of the Pyeongyang Declaration.

"I think he suggested not only the facility dismantling, but also the big piece on the inspection side because if you don't know how many weapons they have, we cannot talk about how to eliminate it or even reduce it. On that point, if we are talking about the dismantling of facilities without even the concrete schedule to do so, probably is a let down for a lot of people."

Other experts, like writer Tim Shorrock, say the U.S. might not see this as a positive development -- they'll want something more concrete before another meeting.

"I think the biggest problem is that the United States wants North Korea to basically surrender its nuclear weapons first and then move toward peace regime and getting a peace treaty... I think that North Korea is not going to surrender its weapons without some kind of real security that not only just guarantee, but its future where it feels under attack by the United States."

Shorrock said key steps by both North Korea and the U.S. are needed to improve their communications -- perhaps by opening up embassies or liaison offices in Pyeongyang and Washington.
Cha Sang-mi, Arirang News.