Kelly, assistant US secretary of state for East Asian and Pacific affairs, was to sit down with Mitoji Yabunaka, head of the Japanese foreign ministry's Asian and Oceanian affairs bureau and South Korean Deputy Foreign Minister Lee Soo-Hyuck for the first time since last month's six-way talks in Beijing.

Kelly arrived in Tokyo in the afternoon, a US embassy spokeswoman said without elaborating, for informal talks due to get underway late Monday.

The talks would focus on preparations for a new round of six-way talks also involving North Korea, China and Russia, a foreign ministry official said.

"As they will discuss measures to (stem) the crisis, preparations for a new round of six-way talks are, of course, expected to be among items on the agenda," the ministry official said.

Japan and South Korea held bilateral talks ahead of a working dinner with the US delegation, but the ministry declined to confirm any details of the three-way meeting, including whether it had started, saying the parties had agreed not to comment on the proceedings.

A weekend report in the mass-circulation Yomiuri Shimbun daily said Japan would ask the United States to state specific terms under which it would provide North Korea with a "security guarantee."

Citing Japanese foreign ministry officials, Kyodo News agency said last week that the allies would discuss setting up a system to verify whether North Korea is dismantling its nuclear arms program, to involve experts from various countries and the International Atomic Energy Agency (IAEA).

Pyongyang has demanded a non-aggression pact with the United States as a prerequisite for abandoning its nuclear weapons ambitions.

Washington has insisted that North Korea scrap its nuclear weapons drive before it will consider offering the Stalinist state concessions including economic and security benefits.

Senior officials from the six nations met in Beijing August 27-29 to explore ways to settle a prolonged crisis over Pyongyang's nuclear ambitions.

The talks ended without a tangible agreement, with the delegates agreeing to meet again but failing to fix a date for the next round.

North Korea termed the first round "useless" and accused the United States of refusing to soften its "hostile" policy towards Pyongyang. The isolated nation reiterated the message Thursday with a call for Washington to "buckle down" and resolve the nuclear crisis.

A Chinese foreign ministry official closely involved in the North Korean talks said Friday she saw no signs North Korea would refuse to join future six-party negotiations despite having dismissed them as worthless.

The crisis erupted in October last year when the United States accused North Korea of reneging on a 1994 Agreed Framework nuclear safeguard accord by running a secret uranium enrichment program.

Under that accord North Korea agreed to freeze its nuclear facilities in return for the construction of two light-water reactors and the supply of heavy fuel oil.

North Korea has since kicked out IAEA inspectors and withdrawn from the nuclear non-proliferation treaty after the United States suspended fuel shipments to the energy-starved country.

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