North Korea says that the six-party talks aimed at resolving its nuclear program must first deal with South Korea's undeclared past nuclear experiments.

North Korea's state-run Korean Central News Agency, quoting the North's Foreign Ministry spokesman, said Wednesday that it would be quite natural for the six-party talks to first address the issue, accusing the United States and the International Atomic Energy Agency of trying to "hush up" the South's past nuclear experiments.

KCNA also quoted the spokesman as saying that double standards in regard to the nuclear issues of the two Koreas cannot be accepted under any circumstances.

The spokesman also said that North Korea refuses to take part in six-party talks that aims to unilaterally dismantle what it called its "nuclear deterrent" by blindly adhering to U.S. pressure and IAEA's ungrounded investigation results.

It was the North's first reaction to IAEA's decision last week not to refer South Korea to the UN Security Council over its undeclared extraction of tiny amount o fplutonium and enrichment of uranium.

North Korea was referred to the UN's highest decision-making body last year after it seceded from the Nuclear Nonproliferation Treaty amid a deepening standoff with the United States.