North Korea handed over a long-delayed account of its nuclear activities on Thursday, prompting the United States to ease sanctions but leaving questions about the communist state's atomic ambitions.
US President George W. Bush cautiously welcomed the action but warned North Korea, which tested a nuclear device two years ago, that it faced consequences if it did not fully disclose its operations and continue to dismantle its nuclear program.
"If North Korea makes the wrong choices, the United States and our partners in the six-party talks will respond accordingly," he said at the White House in Washington shortly after the declaration was handed over to China.
"If they do not fully disclose and end their plutonium, their enrichment and their proliferation efforts and activities, there will be further consequences," said Bush, who once branded North Korea part of an "axis of evil."
He quickly took a step toward removing North Korea from the US list of state sponsors of terrorism, which will take 45 days, and issued a proclamation lifting some sanctions under the US Trading with the Enemy Act.
Bush's national security adviser Stephen Hadley told reporters that easing those sanctions was "relatively minor" and that if Pyongyang failed to fulfil its obligations the United States could seek reimpose them or push for new ones.
"If they are unwilling to carry out their obligations then there will be consequences," he said. "To the extent applicable and to the extent we can do it legally we would reimpose past sanctions. We would also have the option to get additional sanctions but it would not be just the United States."
Bush also welcomed an announcement by North Korea that it would blow up the cooling tower at Yongbyon, its main nuclear complex, but said these were all initial steps by the reclusive communist country and more work was required.
In an unprecedented move, North Korea has invited Western media to record the event. North Korea had already begun dismantling its nuclear facilities after talks among China, Japan, Russia, North and South Korea and the United States.
"This isn't the end of the process, this is the beginning of the process," Bush said, and added Pyongyang's current actions would not in themselves end North Korea's international isolation.
He said among other steps North Korea needed to take was a resolution of its differences over abducted Japanese citizens. North Korea at this stage has also given no details of its existing nuclear arsenal, an issue which will be addressed in another phase of the six-party talks.
Experts on the long-running dispute said the declaration was a step forward, but deepened uncertainties about who will make further concessions, and how much other countries are willing to trust Pyongyang.
"Since this particular declaration has not included nuclear weapons or the exact number of warheads they have, that is a key concern. The other thing is whether or not the North Koreans have stopped work on the uranium enrichment program and how far that has gone," said Lee Chung-min, a professor at Yonsei University in Seoul.
China, the closest Pyongyang has to an ally, hosted the six-country talks that last year secured a deal offering North Korea energy, aid and diplomatic concessions in return for disabling its main nuclear facility and unveiling past nuclear activities.
"We believe we have ... the means by which to verify the completeness and accuracy of this document," US Secretary of State Condoleezza Rice said as she travelled in Japan.
"For instance, in order to verify the plutonium number that the North Koreans have given, we have been given documents, but we also are expecting access to the reactor core, to the waste pool," she said, referring to the nuclear reactor at Yongbyon.
The latest phase of the nuclear disarmament deal had been due for completion by the end of 2007 but was delayed by wrangling over money, aid and the contents of the declaration.
The chief US envoy to the six-party talks, Assistant Secretary of State Chris Hill, told reporters North Korea's declaration was likely to be soon followed by a new round of negotiations. Deputy Russian foreign minister Alexei Borodavkin told Interfax news agency a meeting next week had been discussed.
Bush bracketed North Korea, Iraq and Iran in an "axis of evil" after the September 11 attacks, accusing them of state-sponsored terrorism and seeking weapons of mass destruction. Removal from the US list of state sponsors of terrorism would ease trade restrictions and open the way for other cooperation with the United States, and eventually let Pyongyang work with the World Bank and other international institutions.
"What happens after the declaration will largely depend on domestic political factors in the United States," said Shi Yinhong, a regional security expert at Renmin University in Beijing.
"If US domestic pressure is not big, President Bush will have room to offer North Korea more concessions before his term ends." Bush and other officials stressed the symbolic nature of the US trading concessions. His Republican administration has come under strong pressure from many conservatives not to be seen as compromising on North Korea five months before a US presidential election in which national security issues will play a big part.