A top nuclear nonproliferation official in the U.S. says Washington will not recognize North Korea as a nuclear weapons state and that the U.S. is firm in its stance that the Korean Peninsula must be nuclear-free.

White House Coordinator for Weapons of Mass Destruction, Security and Arms Control Gary Samore’s comment is in response to the North Korean Foreign Ministry’s claim that it would participate in nuclear disarmament efforts on the condition that Washington acknowledges North Korea as a nuclear state.

In a lecture at the Carnegie Endowment for International Peace in Washington, Samore stressed that all members of the six-party denuclearization talks, excluding North Korea, are of the stance that there must be no nuclear weapons on the Korean Peninsula.