(CNN) -- North Korea's Foreign Ministry blamed the United States Friday for the stalemate in nuclear talks, saying America's "unjust" demands would have a "serious impact" on denuclearization.
"If the U.S. ... delays the settlement of the nuclear issue, it would have a serious impact on the disablement of nuclear facilities," an unidentified spokesman for North Korea's Foreign Ministry said in a statement carried by the Korean Central News Agency, the North Korean news agency.
The U.S. State Department has said North Korea must provide a complete declaration of its nuclear program to the United States and its partners in talks on the nuclear issue -- Russia, China, Japan and South Korea -- to break the deadlock.
Previously, North Korea blamed the deadlock on the United States failing to honor its promise to remove North Korea from its list of countries that sponsor terrorism.
But the State Department said North Korea can't get off the list without a full accounting of its nuclear program.
"This declaration must include all nuclear weapons, programs, materials and facilities, including clarification of any proliferation activities," U.S. Assistant Secretary of State Christopher Hill told the Senate Foreign Relations Committee last month.
Pyongyang agreed last year to dismantle its nuclear program in exchange for economic aid and better relations with the United States.
The State Department says North Korea has completed a majority of work related to disabling a plutonium-making facility at Yongbyon, but still has more to do.
Used to the often blustery rhetoric from its neighbor, Seoul said it doesn't take seriously North Korea's threat to backtrack on denuclearization.
"We don't see it as a matter of concern," Foreign Ministry spokesman Moon Tae-young told Yonhap. "It is viewed as routine." E-mail to a friend 
All About North Korea • Nuclear Proliferation • Christopher Hill
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