Itsunori Onodera said North Korea agreed to give up nuclear weapons as early as 1994, but has continued to develop them in secret and until a year ago threatened surrounding countries with a series of ballistic missile launches.
High-ranking officials from the United States and North Korea met over two days to discuss the future of Pyongyang's nuclear weapons program and the much-anticipated summit between Mr Trump and Mr Kim.
"The difference of the position between the North and the United States in the denuclearization of the Korean Peninsula is still huge", South Korea's unification minister, Cho Myoung-gyon, said on Wednesday, as NK News noted.
The current rapprochement on the peninsula was triggered by the games, to which the North sent athletes, cheerleaders, and his sister as an envoy.
Trump had previously cancelled the summit on May 24, citing a "recent statement" by North Korea as the cause for the cancellation.
The meeting followed two landmark summits between the leaders of North and South Korea in the last five weeks.
"I think they want to do that".
Trump said the lengthy conversation Friday "went very well" and called it "a get to know you kind of a situation".
"We're going to discuss it prior to the meeting".
Chol traveled to Washington D.C. Friday morning after meetings in NY with Secretary of State Mike Pompeo.
He said the meeting with the senior North Korean official "went really well".
Whether the summit happens on June 12 or not, it will be a long process and involve many meetings. Hours later, Trump said the summit was potentially back on.
The flurry of diplomacy has also seen a rapprochement on the Korean peninsula, with the two Koreas holding high-level talks Friday at the border truce village of Panmunjom.
"Our movement is committed to the abolition of nuclear weapons and we recognize that this historic summit is a once in a generation opportunity to work for peace and nuclear disarmament", Akira Kawasaki, an ICAN worldwide steering group member, said in a statement.
"We will calmly, and with expectation, watch the historic meeting in Singapore".