There's also a possibility that the leaders will reach a deal to cancel or postpone the drills in the meeting scheduled to take place in Vietnam from February 27-28.
Officials have said that there must first be tangible progress in denuclearization negotiations between the USA and the North so that Washington can ease sanctions and allow inter-Korean cooperation projects to move forward.
Will North Korea open up to the world in 2019, or renew its threats of nuclear war? . South Korea is split along generational and ideological lines on how to handle the North.
In a report earlier this week, it said actions including the illegal transfer of banned goods at sea could make sanctions - the worldwide community's main way of putting pressure on North Korea - "ineffective". Mr. Biegun is expected to come to South Korea to brief officials as early as Friday.
Palladino also said he has no additional announcement at the moment regarding the schedule of U.S. Special Representative for North Korea Stephen Biegun, who is visiting Pyongyang for working-level talks with North Korea to prepare for the summit.
"I look forward to seeing Chairman Kim & advancing the cause of peace!" he said.
The announcement came after the top USA envoy to North Korea wrapped up three days of talks with his counterpart in Pyongyang.
North Korea has repeatedly urged a lifting of punishing US -led sanctions, a formal end to the war, and security guarantees.
The Singapore summit yielded a vague commitment by Kim to work toward the denuclearization of the Korean peninsula, where USA troops have been stationed since the Korean War.
Hanoi is a place that was much preferred by the North Korean side.
But a report to the UN Security Council on Monday suggested North Korea was continuing its nuclear and missiles programmes, while making efforts to protect its facilities from possible future strike.
The President also appeared to reference his previous mocking of Mr Kim as the "Little Rocket Man". Japan's Fuji TV quoted Vietnamese government sources as saying that Trump administration officials arrived in Da Nang on Wednesday afternoon.
"I am confident that if both sides stay committed, we can make real progress", he told reporters. But Washington has insisted that North Korea needs to first take more concrete steps toward denuclearization.