," he said, stressing the government is still analyzing the information.

Hirano urged North Korea to quickly return to the six-party talks aimed at denuclearizing the country.

The nuclear disarmament talks, involving the two Koreas, the U.S., China, Japan and Russia, have been stalled since last December, with Pyongyang's effective exit.

In April, North Korea officially withdrew from the talks and said it would start reprocessing nuclear spent fuel rods to produce plutonium to protest U.N. criticism of its rocket launch earlier that month. The reprocessing was apparently finished in August.

The announcement by Pyongyang's official Korean Central News Agency, which came a day after Pyongyang repeated a call for direct talks with Washington, is viewed as an attempt to draw the United States into such talks to address the nuclear standoff.