North Korea says it will not allow the removal of nuclear samples from its key nuclear facility.

In a statement carried by its Foreign Ministry Wednesday, North Korea said the extraction of nuclear samples was not included in its agreement with the U.S. on the North’s nuclear verification. The statement said the accord confined the methods of verification to field visits, document confirmations and interviews with scientists.

The statement warned that attempts to violate the boundaries of what was agreed upon in the accord will be construed as a breach of the North’s sovereignty that would ultimately lead to war.

The North’s statement differs in content with a statement issued by the U.S. State Department last month. On October 12th, the department’s spokesman Sean McCormack said the accord on Pyongyang’s nuclear verification contains all factors needed to verify the North’s nuclear programs and materials.

Pyongyang and Washington are also showing differences in the scope of verification. The North says verification will be confined to its Yongbyon nuclear reactor, while the U.S. says verification will be conducted not only on plutonium-related plants, but also facilities that are linked to uranium enrichment and nuclear proliferation.

The North’s statement also expressed discontent over a delay in economic aid to Pyongyang. It said nuclear verification will come only after all compensation for the North’s nuclear disablement is received.

With the North’s move, it has become uncertain when a new round of six-way nuclear talks will open and whether Pyongyang’s nuclear disablement will be completed before the end of the Bush administration.