Since 2017, North Korea has frozen nuclear and missile testing.
Moon, special presidential adviser for foreign affairs and national security, cited the possibility of the butterfly effect to bring about a "catastrophe".
South Korea's Joint Chiefs of Staff (JCS) says Seoul is closely tracking and monitoring North Korea's missile activities in coordination with the United States.
Though respected by academics and journalists for his knowledge, candor and lack of fear of controversy, Moon frequently infuriates conservatives in South Korea and the United States for what they consider to be his pro-North Korea bias.
All these actions will be coordinated in advance with the United States and Washington and Pyongyang are expecting to return to the negotiating table to reach an agreement on denuclearization. "I think Kim Jong Un has a very clear idea where the president stands". On the other hand, US officials consider it as an economic matter connected with the North's funds for weapons development.
Gause, on the other hand, thinks inter-Korean economic projects could help US negotiate denuclearization with North Korea.
John Bolton told "This Week" co-anchor Martha Raddatz on Sunday that it's possible the South Korean government has spoken to North Korea about the activity.
"The president's confident in his personal relationship with Kim Jong Un".
At the White House on Monday, spokeswoman Sarah Sanders scoffed at reports that China was wary of holding a summit with Trump on trade after he walked out of his meeting with Kim without a deal. "Why should North Korea believe that at the end of this rainbow they'll get a pot of gold?"
"What North Korea needs - and it needs it very much right now - is economic relief".
"But we can't comment on concrete details", he added.
And it notes a trend in North Korea's evasion of financial sanctions by "using cyberattacks to illegally force the transfer of funds from financial institutions and cryptocurrency exchanges".
The summit collapsed because the US president said that Kim Jong Un asked for the sanctions to be completely scrapped in exchange for the dismantling of NoKor's Yongbyon nuclear complex.
The North's state-controlled media has stayed away from direct criticism of Trump.
Washington and Pyongyang accuse each other of causing the summit's breakdown, but both sides have avoided harsh criticism against each other and expressed hopes for future negotiations. 'We could lose momentum, ' the advisor fretted.
"We are not going to do denuclearisation incrementally".
Moreover, the clock is ticking on the Trump presidency.
Moon says the Hanoi summit showed how "difficult" and "painful" to achieve denuclearization on the Korean Peninsula.
"This will be something we would like to get done in the President's first term". I don't really think it broke down.
The election for the 14th Supreme People's Assembly, however, has drawn attention from outside observers as its outcome could provide a rare glimpse of any shift in North Korea's very closed elite structure. 'North Korea's survival strategy is hedging, ' he said.