A group of senior US Democrats has urged the Bush administration to begin direct talks with North Korea, warning that the secretive state poses a far greater threat of becoming a hostile nuclear power than Iraq.
Sandy Berger: time may be running out
Former Defence Secretary William Perry, who is heading a newly formed group advising Senate Democrats, described the Koreas as "the most dangerous spot in
the world today".
Washington has so far baulked at the suggestion of face to face talks with Pyongyang, anxious not to be seen to be responding to nuclear blackmail, and to keep discussions within a multilateral framework.
But Sandy Berger, a former National Security Adviser, warned that "time is not our friend".
Last month North Korea restarted its nuclear reactor at Yongbyon. It is believed to have enough spent fuel rods to make at least five nuclear warheads.
The first of these could be ready in a matter of weeks, if Pyongyang restarts a separate nuclear reprocessing plant.
North Korea is also known to have missiles capable of hitting Japan. According to Japanese media reports, the US is concerned that Pyongyang is currently gearing up to test-fire a Nodong missile, which has a range of about 1,300 kilometres (813 miles).
Map shows range of Taepodong 1 missile, flown over Japan in 1998. Range 1,500-2,000 km, payload: 1,000 kg
North Korea also thought to be developing Taepodong 2. Range up to 8,000 km (could reach western US)
Other missiles: Scud-B: Range 300 km, payload 1,000 kg
Scud-C: Range 500 km, payload 7600-800 kg
Scud-D (Nodong): Range 1,000-1,300 km, payload: 700-1,000 kg
Mr Berger told the BBC that North Korea should not be put on the "back burner", while the US focused on Iraq.
"We're now on the verge of a situation in which North Korea could be a nuclear weapons factory, producing either nuclear fuel - plutonium - or nuclear weapons and selling them to terrorist groups or rogue states," Mr Berger told the World Today programme.
"North Korea, unlike Iraq, actually has a proven record of selling its sophisticated weapons technology," he said.
Dealing with North Korea and Iraq, Mr Berger said, was not an either/or choice.
It was "essential" for the US to hold direct talks with North Korea to determine whether a negotiated settlement was possible, and if it was not, then "more robust" action could be considered, along with the US' regional allies, Mr Berger said.
But he warned that as long as Washington shied away from face to face discussions with the North, then the Bush administration would remain divided from its allies, "and that means we have no real leverage" over Pyongyang.
Furthermore, Mr Berger said, the continuing stand-off could have a "cascading effect" on security in the region and give North Korea a chance to enter into "the deadly commerce of terrorism".
The Chinese Foreign Minister, Tang Jiaxuan, on Thursday reiterated Beijing's call on Washington to hold direct talks with North Korea.
The US has instead urged Beijing, an ally of North Korea, to use its influence to persuade Pyongyang to give up its nuclear weapons programme.
But Beijing fears that pressure or sanctions could ratchet tensions further, or ultimately bring down the regime in Pyongyang, sending millions of refugees over the border into China.
16 Oct: US says N Korea admits to a secret nuclear programme
14 Nov: US halts oil shipments to N Korea
22 Dec: N Korea removes monitoring devices at Yongbyon nuclear plant
31 Dec: UN nuclear inspectors forced to leave
10 Jan: N Korea pulls out of anti-nuclear treaty
12 Feb: IAEA refers issue to UN Security Council
27 Feb: US says Yongbyon reactor restarted
Despite Washington's official refusal to hold talks with North Korea, there was a sign on Thursday that, behind the scenes at least, diplomacy is continuing.
The Japanese news agency Kyodo reported that nuclear experts from the North and the US held private talks in Berlin on the issue last month.
But the public face of North Korean-US relations on Thursday was less conciliatory.
American military officials said the first of 24 additional long-range bombers arrived on the Pacific island of Guam, sent to deter any possible escalation by North Korea.
A spokeswoman said the deployment of the B-1s and B-52s was not aggressive, but it is sure to be interpreted as such by Pyongyang.
North Korea has been embroiled in a tense stand-off with the US since news broke in October of a secret North Korean nuclear programme.
The US stopped fuel aid to North Korea, which reacted by kicking weapons inspectors out of the country and restarting its Yongbyon nuclear reactor.
It also pulled out the nuclear Non-Proliferation Treaty, which seeks to control the spread of nuclear arms.