The United States Tuesday called North Korea's announced decision to suspend the disablement of its nuclear facilities a "step backward" in the six-party disarmament process. North Korea said it took the step because it has not been taken off the U.S. list of state sponsors of terrorism. VOA's David Gollust reports from the State Department.

U.S. officials say the North Korean announcement is of great concern and they are expressing hope it does not signal any intention on the part of Pyongyang to roll back progress made in the six-party process.

In this 27 Jun 2008 file photo provided by China's Xinhua News Agency, ruins of Yongbyon nuclear complex's cooling tower are seen

North Korea said it was halting the disabling of its Yongbyon nuclear complex, and would consider restoring the main reactor there, because of the United States refusal to remove it from its list of state sponsors of terrorism.

President Bush, in late June, announced his intention to take North Korea off the blacklist, dependent on Pyongyang providing an acceptable verification program for the declaration of its nuclear holdings it made at that time.

In a talk with reporters, State Department deputy spokesman Robert Wood said North Korea is well-aware of what it needs to do to be taken off the terrorism list and that it should provide the long-awaited verification plan.

Wood said stopping the disabling process at Yongbyon would be a step backward and certainly a violation of the principle of "action-for-action" that has guided disarmament process.

"Its obviously something we view with great concern. It's  in violation of commitments they've made in the six-party framework, and its clearly a step backward," he said. "And we'll be having discussions with our other partners in the six-party talk to see how things play out in the coming weeks."

North Korea shut down the Yongbyon reactor and committed to  permanently disabling the facility in exchange for energy aid in the first phase of the Chinese-sponsored six-party accord finalized in 2007.

The provision of a verification program for the North Korean declaration would open the way to the next phase of the accord, in which Pyongyang is to scrap its nuclear program in exchange for, among other things, and end to terrorism-related U.S. sanctions and various diplomatic benefits.

Wood declined to say how the North Korea decision was communicated to the United States, but said the U.S. understanding is that that the move is "temporary."

He expressed hope the decision would not lead to resumed operations at the Yongbyon reactor, which produced the plutonium for North Korea's presumed small arsenal of nuclear weapons.

He noted that there have been "ups and downs" in the disarmament deal and that he wouldn't preclude further complications before the intricate process is complete.