"Given the historical importance of the upcoming summits [inter-Korean Summit and the DPRK-U.S. Summit], the President of the Republic of Korea can not leave the country". A successful summit between Moon and Kim could pave the way for a meeting between Kim and U.S. President Donald Trump - the first between a sitting American president and a North Korean leader.
The communist state staged almost a dozen missile launches in less than seven months after Moon's inauguration, while also conducting its sixth and most powerful nuclear test so far in September.
But tensions have eased in recent months, coinciding with North Korea's participation in the Winter Olympics held in the South in February.
North Korean leader Kim Jong-un (right) shakes hands with South delegation leader Chung Eui-yong in this photo released by North Korea's Korean Central News Agency March 6, 2018.
During started after this high-level dialogue was the date for the inter-Korean summit on April 27.
He added it will likely focus on issues of denuclearisation and peace on the Korean peninsula, and an improvement in relations not only between the two Koreas but also with other countries including the United States. "We are about to embark on a great transition of complete denuclearization of the Korean Peninsula, lasting peace and sustainable development of South-North Korean relations in the history of the world", he said earlier.
"Kim will act during his summits with Seoul and Washington as if he were determined to dismantle nuclear weapons in stages - first declaring dismantlement followed by incapacitating nuclear weapons and denuclearization", it quoted Thae as saying.
"That itself shows that the North understands it needs to first sort things out with the South before it can reach an actual deal with the US", a Cheong Wa Dae official said, noting that the North long insisted on talking directly and only with the USA when it came to nuclear and security issues.
Thae Yong-ho was quoted on Monday as saying that North Korean leader Kim Jong-un "will drag on for two to three years" without dismantling his nuclear weapons "while waiting for the USA president to be replaced".
North Korea and the rich, democratic South are technically still at war because their 1950-53 conflict ended in a truce, not a peace treaty.