The Trump-Kim summit in June of this year was created to help ease the tensions between the two nations - though critics have questioned whether North Korea has complied with agreements reached at the historic meeting.
Those events, combined with a recent North Korean threat to renew overt nuclear development should Washington continue opposing sanctions relief, suggested to many analysts that the countries are having problems seeing eye-to-eye, calling into question when a second summit might take place.
North Korea entered into agreements with regional powers in 1994 and in 2005 to dismantle its nuclear programme in return for economic benefits and diplomatic rewards, but those deals broke down after Pyongyang clandestinely continued to pursue building weapons of mass destruction.
China's influence as North Korea's largest trading partner is viewed as key to any significant agreement between the USA and North Korea.
The White House said he reaffirmed that plan during a meeting with Moon Friday on the sidelines of the G20 summit in Argentina. "It is North Korea which should clearly state and show by taking actions, then I am sure that there will be no reason why the Security Council of the United Nations will continue to impose the sanction on North Korea".