Lyu Chao, director of the Border Study Institute at the Liaoning Academy of Social Sciences, said it should be recognized that the settlement of the nuclear issue is an extremely complicated process.

"It does not happen overnight," he said, adding that Trump's course reversal fully demonstrated that the Korean Peninsula issues require more cautious decisions and should not be made impulsively.

Washington's demand for a "complete, verifiable and irreversible denuclearization" is inconsistent with Pyongyang's intention to achieve denuclearization gradually, said Zheng Jiyong, director of the Korea Research Center at Fudan University, adding that the ideal way to work on the issue is that both parties can "move toward the same goal, make concessions, and show their sincerity", he said.

On Saturday Kim and Moon also announced that the two leaders would meet frequently in the future to make dialogue brisk and to pool wisdom and efforts, and also promised to further push forward the peace process on the Korean Peninsula by working toward denuclearization and improved inter-Korean ties.