North Korea’s ambassador to the UN in Geneva says relations with Washington could improve quickly if the U.S. responded to Pyongyang’s “efforts with trustworthy measures.”

Speaking at a UN-sponsored conference on disarmament in Geneva on Tuesday, Ambassador Han Tae-song said North Korea has declared it would neither make nor test nuclear weapons and would no longer use and proliferate them.

He stressed that if the U.S. responds to these efforts with trustworthy measures and corresponding practical actions, bilateral relations will "develop wonderfully at a fast pace" through the process of taking more definite and epoch-making steps.