Secretive North Korea was preparing a global TV spectacular Friday to dramatise its commitment to scrapping nuclear weapons, as world powers gave a wary welcome to its disclosure of some atomic secrets.
The communist state was set to blow up the cooling tower at the plutonium-producing Yongbyon complex -- the most visible symbol of a decades-old pursuit of nuclear bombs.
The explosion at an undisclosed time will be symbolic since the Yonbyon reactor has already been shut down under a six-nation disarmament pact.
But it follows the North's handover Thursday evening of a long-awaited nuclear declaration, a move expected to end the stalemate in six party negotiations.
US President George W. Bush welcomed the declaration as an "important step" but only the start of the process.
"We will trust you only to the extent that you fulfil your promises," he told the country he once branded as part of an "axis of evil."
Bush announced he was partly lifting some Trading With The Enemy Act sanctions. He notified Congress he was removing North Korea from the US list of state sponsors of terrorism, effective after a 45-day review period.
These measures are also largely symbolic since a battery of other sanctions against the North remain in force -- including UN sanctions imposed after the country's October 2006 nuclear test.
The delisting can be put on hold if the North fails to meet US demands that it allow its declaration -- especially the size of the plutonium stockpile -- to be verified.
The declaration delivered to six-party talks host China is said to give details of nuclear facilities and of Yongbyon's production over the past two decades of plutonium for bomb-making.
It does not disclose any information on nuclear weapons, an issue to be tackled in the next phase of the six-party deal.
US National Security Adviser Stephen Hadley said the report did not answer US allegations of nuclear proliferation to Syria, or its claims of a past secret enriched uranium weapons programme.
"We're in a situation of not quite admitting, not denying, but opening the door for us to be able to try and get greater clarity," Hadley said.
UN Secretary General Ban Ki-moon called the North's move a "very encouraging development" but Japan urged the United States and other nations to maintain close surveillance of disarmament moves.
US Secretary of State Condoleezza Rice said North Korea must grant access to the reactor core and radioactive nuclear waste. But she called the 60-page document a "good step forward."
The impoverished North is getting one million tons of fuel oil or equivalent energy aid, plus the terrorism delisting, in return for disablin g its Yongbyon plants and delivering the declaration.
The six parties -- North and South Korea, Japan, Russia, China and the United States -- are expected to meet in Beijing next month to discuss ways to verify the document, complete disablement and prepare for the final phase -- dismantlement of plants and handover of all nuclear material including weapons.
In return the North would secure diplomatic relations with its decades-old enemies the United States and Japan, along with "lasting peace and stability" in the region.
Rice, under fire from conservative US critics who say she is giving away too much, has said it may well be true that the North is unwilling to take the final step of giving up its nuclear weapons.
"But we and our partners should test it," she said earlier this month.
Before Yongbyon shut down last July, foreign analysts would watch for smoke from the 30-metre-tall (99 foot) cooling tower to see if the reactor was operating.
TV crews from North Korea's fellow negotiating nations have been invited to witness its destruction and to broadcast it around the globe.
