"I said I will suspend the nuclear debate for a while but I believe the issue of the threat to Japan has to be discussed," Nakagawa told a small group of French journalists.

After North Korea tested an atom bomb last month, Nakagawa called for Japan to debate whether to develop nuclear weapons -- a longtime taboo in the only country to have been attacked with atomic bombs.

His statement was supported by Foreign Minister Taro Aso. Prime Minister Shinzo Abe, a conservative who is close to Nakagawa, has rejected even considering the nuclear option but said his aides had the right to speak out.

"I have never denied my own comments. But after I spoke there have been changes in the North Korean situation along with the US midterm vote results," Nakagawa said.

"After considering these changes in the international environment, I am changing my stance."

US President George W. Bush's Republican Party suffered a severe defeat to the rival Democrats in congressional elections last week.

Bush has branded North Korea part of an "axis of evil" and refused bilateral talks with Pyongyang -- an option favored by many Democrats.

Nakagawa said Japan, like the Bush administration, preferred the six-nation format, which includes China, Japan, Russia and South Korea.

"It's no good," he said of bilateral talks. "The basis of the negotiations is the six-party talks."

Nakagawa's calls for a nuclear debate have set off criticism from neighboring countries, with Russia warning of a regional arms race.

Abe has refused calls from the opposition to sack Aso, the foreign minister, to show his commitment against nuclear weapons.

Abe, Japan's first premier born after World War II, has supported a larger military role for Japan including rewriting the US-imposed 1947 pacifist constitution.

His cabinet on Tuesday reiterated its stance that Japan has the legal right to nuclear weapons even though it will not pursue the option.

"Purely from a theoretical viewpoint, the possession of a necessary minimum of nuclear weapons does not necessarily mean that it violates Article 9 of the constitution" which bans the use of force in solving international disputes, said a statement approved by the cabinet.

But the statement, issued in response to a question from a parliament member, said that the cabinet "does not have the intention of discussing the need to review the non-nuclear principles."

It was referring to Japan's 1967 policy of refusing the possession, production or presence of nuclear weapons on its soil.

US nuclear bombs obliterated Hiroshima and Nagasaki in the final days of World War II, killing more than 210,000 people.

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