President Moon Jae-in was set to embark on a five-day trip to New York on Monday to attend the UN General Assembly and hold talks with other leaders on how to rein in North Korea's evolving nuclear and missile provocations.
His trip follows North Korea's sixth nuclear test on Sept. 3 and a series of missile firings.
The presidential office Cheong Wa Dae said earlier Moon will hold a luncheon and summit with the leaders of the United States and Japan in New York on Sept. 21.
The official, speaking on condition of anonymity, said the communist state's continuing provocations will likely top the agenda for the three-way summit.
"At the three-nation summit, the leaders will hold in-depth discussions on ways to strengthen close cooperation in dealing with the North Korean nuclear and missile issues and enhance their cooperation with the international community," the official said.
Pyongyang fired what appeared to be an intermediate range ballistic missile that flew across Japan on Friday, marking its 16th missile provocation since the start of the year and 10th since the Moon Jae-in administration took office in May.
In his speech at the UN General Assembly later this week, the South Korean leader is expected to call for international efforts to further isolate the impoverished North.
Moon, an advocate of engagement with the North, continues to insist the North Korean nuclear issue must be resolved peacefully through dialogue.
However, following the North's recent repeated provocations, the South Korean president has said dialogue may not be possible, at least for now.
"International sanctions and pressure will further tighten to force North Korea to choose no other option but to step forward on the path to genuine dialogue," he was quoted as saying while attending an emergency National Security Council meeting on Friday to discuss the North's latest missile provocation.
While in New York, the South Korean leader is also expected to hold talks with other global leaders, though Cheong Wa Dae said the list of the leaders he will meet has not yet been fixed.
He will return home Friday. (Yonhap)