"Acting as a diplomatic mediator, Moon is following a dual-track strategy to engage Kim while keeping the US onside," she said.

"The real question is not how soon will Kim give up his nuclear weapons but whether and how the ROK and the DPRK will continue their peace process after a year that saw some of the most dramatic steps toward Korean reconciliation since the end of the Korean War," Lee added.

The ROK's cargo trains operated five times a week for about one year through the section of the Gyeongui Line from Kaesong to Munsan, but the operation stopped in December 2008 as inter-Korean relations began to sour.

Kim Kum-ok, a ROK-separated family member whose birthplace is Kaesong, said in the train for the Panmun Station that she rejoiced and enjoyed her trip to Kaesong where the 86-year-old spent her early years, according to a pool report from Seoul's unification ministry.

Describing the trip as a dream, Kim said the train trip to her hometown had been a big hope to her.