North Korea denounced U.S. leaders as "warmongers" on Saturday and called Japanese officials "political imbeciles" for saying they won't accept Pyongyang as a nuclear power.

In typically harsh rhetoric, the reclusive communist state demanded Japan stay away from international disarmament negotiations, which also include China, Russia, the U.S. and South Korea.

The North agreed earlier this week to return to the talks, the first relaxation of tension after its Oct. 9 nuclear test. The talks have been stalled for a year.

A statement from North Korea's Foreign Ministry on Saturday said there was no need for Japan to participate in the talks "because it is no more than a state of the U.S."

The Foreign Ministry said most of the international community had welcomed North Korea's return to the talks. "Only Japan that expressed its wicked intention," referring to comments by Tokyo that it will not accept a nuclear North Korea.

"The Japanese authorities have thus clearly proved themselves that they are political imbeciles," added the statement, carried by the North's official Korea Central News Agency, or KCNA.

Japan's Foreign Ministry said the government was aware of North Korea's statement, and was considering a response.

The North also kept up its verbal attack on the United States in an editorial by the typically bellicose Rodong Sinmun newspaper.

"The U.S. has become more fanatic in pushing for its war scheme to attack the North, taking issue with our war-deterrent measure we were compelled to strengthen to protect our sovereignty and right to survive from their serious threat," the editorial said.

The North often refers to its nuclear program as a self-defensive measure against the threat of a U.S. attack — an accusation Washington has repeatedly denied.

Meanwhile, the North's leader Kim Jong Il visited an army unit, KCNA reported late Friday, his first public military visit since last month's test and the first known public appearance after the country agreed to return to the arms talks. It was not clear from the report when Kim made the visit.

North Korea's remarks came after the nation's No. 2 leader, Kim Yong Nam, said any progress at the revived talks on the communist nation's nuclear program will depend on the United States, an indication a breakthrough could be difficult.

Kim accused the U.S. of seeking the resumed nuclear talks to bolster Republicans ahead of next week's elections, casting doubts on Washington's sincerity in resolving "fundamental problems between North Korea and the U.S," according to statement on the DLP Web site.

The North Korean official claimed it was Pyongyang which had proposed returning to the negotiations as a way for the U.S. to save face and not appear to be caving in to the North's demand that the financial issue be discussed, the statement said.

That account contradicts U.S. statements that diplomacy by China, the North's last major ally, had been instrumental in luring the North back to the nuclear talks.