North Korean leader Kim Jong-un told President Moon Jae-in during a summit that submitting an inventory of his country's nuclear arsenal and facilities to the U.S. could spark an attack, national security adviser Chung Eui-yong said Tuesday.

"Before trust is built up between the U.S. and North Korea, demanding that we give the U.S. a list of our fissile materials, nuclear weapons and delivery systems is the same as telling us to submit a list of targets for attacks," he quoted Kim as saying.

Speaking at a National Assembly hearing, Chung added, "North Korea is aware that reporting a list of its nuclear weapons is a very important step toward denuclearization, but he feels the process must come after concrete measures are taken to build up trust by both sides."

"We are continuing negotiations with related countries to ensure a declaration officially ending the Korean War within this year as promised and we are very open when it comes to the format," he said.

North Korea has been pushing for such a declaration before it takes any further steps toward denuclearization, but Washington fears that this would rob it of a powerful negotiating card.

The U.S. and North Korea are set to hold high-level talks in New York on Thursday. The U.S. State Department said in a statement on Monday that Secretary of State Mike Pompeo and Kim Yong-chol, vice chairman of the North's Central Committee of the Workers Party "will discuss making progress on all four pillars of the Singapore Summit joint statement, including achieving the final, fully verified denuclearization."