The North Korean statement complicates efforts by the United States and its allies to restart six-nation nuclear talks. Washington considers Japan's participation in the talks crucial, saying North Korea's nuclear programs threaten regional security.
In August, the United States, China, Russia, the two Koreas and Japan held talks in Beijing aimed at addressing the North's nuclear ambitions. Tokyo used the talks to raise another issue it considers pivotal — abductions of its citizens decades ago by the communist state.
On Tuesday, North Korea's Foreign Ministry said it "would not allow Japan to participate in any form of negotiations for the settlement of the nuclear issue in the future."
It was unclear whether the statement, carried by the North's official news agency KCNA, meant North Korea could agree to a future meeting if Japan is excluded. Since the August meeting ended without plans for a next round, North Korea has said it is no longer interested in further talks.
"Japan is nothing but an obstacle to the peaceful settlement of the nuclear issue between the DPRK and the U.S.," the North Korean statement said, using the acronym of the North's official name, Democratic People's Republic of Korea. "It has lost its qualification to be a trustworthy dialogue partner."
North Korea accused Japan of abusing the nuclear talks to raise the "issue of abduction," which the North says has already been settled.
The kidnapping of Japanese during the 1970s and 1980s by North Korea to train its spies has been a major sticking point between the Asian neighbors, stalling efforts to set up diplomatic relations and halting Japan's food aid to impoverished North Korea.
The Japanese public was outraged when North Korean leader Kim Jong Il admitted in September 2002 that his nation's agents had systematically kidnapped Japanese decades ago. North Korea has allowed the return of five kidnapped Japanese.
In Tokyo, the Foreign Ministry said in a statement that if future talks are to occur, "Japan's participation is natural."
"In accordance with the Pyongyang Declaration, the nuclear, missile and abduction issues must be resolved if Japan-North Korea normalization negotiations are to move forward," it said.
Meanwhile, on the Indonesian resort island of Bali, Japan, China and South Korea agreed to coordinate efforts to get North Korea to end its nuclear ambitions and reiterated that the dispute should be resolved peacefully.
The agreement between Japanese Prime Minister Junichiro Koizumi, South Korean President Roh Moo-hyun and Chinese Premier Wen Jiabao came on the sidelines of the annual summit of the 10-nation Association of Southeast Asian Nations.
By Jae-Suk Yoo