"When an appropriate time comes, the DPRK (North Korea) will take a measure to open its nuclear deterrent to the public as a physical force and then there will be no need to have any more argument," a foreign ministry spokesman told Pyongyang's official Korean Central News Agency (KCNA) monitored here.

The spokesman said North Korea "will have no alternative but to take measures to maintain and increase its nuclear deterrent force as means for just self-defence" against the "hostile" policy of the United States.

He declined to elaborate on the "measure" North Korea was considering, but Pyongyang has is the past threatened to carry out a nuclear test.

North Korea threatened to declare itself a nuclear power and test a nuclear device at six-nation nuclear crisis talks held in Beijing two months ago, according to US officials.

A senior US official said then that North Korea would face "consequences" if it made good on the threat.

The two Koreas, China, Japan, Russia and the United States met for the six-way talks for the first time in late August to ease tensions caused by the stand-off over North Korea's nuclear weapons drive.

But the talks ended inconclusively with no date set for the next round, as North Korea later said the meeting was "useless" and it had no interest in further talks, preferring instead to build up its nuclear deterrent.

In the ensuing weeks Pyongyang has raised the stakes by claiming it is making atomic bombs after reprocessing spent fuel rods, and has imposed further obstacles to a new round of negotiations by demanding that Japan be excluded.

In a latest bid to jump-start the six-way talks, South Korea has held cabinet-level talks in Pyongyang this week to coax Pyongyag back to the dialogue table.

US Secretary of State Colin Powell said last week that Washington was working on a security assurance involving multiple nations that he hoped would satisfy the isolated regime.

But Pyongyang has indicated it is unlikely to be satisfied with anything less than a legally binding accord.

North Korea demands a legally binding non-aggression pact from the United States as a first step before responding to Washington's demand for a complete and verifiable dismantling of its nuclear weapons drive.

Pyongyang claims the United States is planning to attack the Stalinist country despite frequent denials from US officials, including President George W. Bush.

WAR.WIRE