John Bolton, a top State Department official, said though Washington hoped to make progress on ending the 13 month-old crisis, it was determined that North Korea would win no reward for "bad behavior."

"Attempts to delay or postpone the six-party talks simply because one or more of the parties wishes to raise issues of vital concern should be rejected," Bolton, considered a hawk on North Korea, said.

"Japan for example feels strongly that it should have the right at least to raise the issue of North Korean abductions of Japanese citizens over the years," said Bolton, under secretary of state for arms control and international security.

"For Japan, this is a fundamental issue, and Japan's desire to raise it should be respected. Japan's participation in the six-party talks is essential."

Bolton's remarks followed a warning by North Korea that Japan was not qualified to take part in the six-nation talks because it wanted to raise the abductions, an issue of prime political importance in Tokyo.

Pyongyang's official media said Japan had "abducted and forcibly drafted" millions of Koreans during its 1910-1945 colonial rule over the Korean peninsula.

"Pretending not to know about this hard fact it is vociferating about the abduction of a few Japanese in a bid to poke its nose into the talks and create a complication there," the Korean Central News Agency (KCNA) said.

It added: "This behaviour has deprived Japan of any qualification to be a trustworthy dialogue partner."

Japan accuses North Korea of abducting Japanese nationals in the 1970s and 1980s to train spies.

Defying strong objections from North Korea, Japan brought up the kidnapping case when the two sides met in the first round of six-way talks in Beijing on Pyongyang's nuclear programme in August.

Tokyo has insisted that the abduction issue should be "comprehensively" settled along with the nuclear issue and the problem of North Korea's missile development and exports.

WAR.WIRE