The United States says North Korea's use of more nuclear fuel for weapons violates the North's past commitments at international disarmament talks.

State Department spokesman Ian Kelly told reporters Tuesday that the Obama administration is focused on getting back to stalled six-nation nuclear talks.

He says that "reprocessing plutonium is contrary to North Korea's own commitments" at those negotiations and violates United Nations resolutions.

North Korea's official news agency says the country had finished reprocessing 8,000 spent nuclear fuel rods. The North has also warned Washington to agree quickly to direct talks or face the prospect of a growing nuclear arsenal.