The Stalinist state's official news agency accused Washington of "driving the military situation on the Korean peninsula to the brink of a nuclear war" with plans for a pre-emptive strike on North Korea.

Cheney is expected in Tokyo on Saturday on the first leg of an Asian tour that also takes him to China and South Korea.

North Korea described six-party talks held in Beijing in February as "fruitless," their harshest assessment so far of the meeting that brought together the two Koreas, China, Japan, Russia and the United States.

"The US demand that the DPRK (North Korea) scrap its nuclear programme first is the main obstacle in the way of solving the nuclear issue between the DPRK and the US," the Korean Central News Agency said in a commentary.

"It is a well-known fact that the second round of the six-way talks held in Beijing last February proved fruitless due to the US demand that the DPRK dismantle its nuclear program first."

Washington is demanding the complete, verifiable, and irreversible dismantling of North Korea's nuclear prorgammes, both plutonium and enriched uranium schemes, before it will offer concessions to the impoverished state.

Pyongyang denies having a uranium programme and has said it will freeze its plutonium weapons programme in return for simultaneous rewards from Washington.

A new round of six-party talks is expected before the end of June while working parties are supposed to be set up to resolve address contentious issues.

South Korea's foreign ministry said all participating countries were ready for working level talks apart from North korea, which has yet to give the go ahead.

In the commentary the North Korean news agency said Pyongyang had no choice but to boost its nuclear weapons drive in the face of US intransigence and its "moves to put the strategy of pre-emptive nuclear attack into practice."

Cheney's trip to Asia has been overshadowed by the deteriorating security situation in Iraq where insurgents are threatening to kill three Japanese hostages unless Tokyo pulls out troops from the war-torn region.

Seven South Koreans were released earlier Friday after also falling into the hands of insurgents.