The gray cooling tower stands 60 feet above North Korea's main nuclear reactor complex, the most visible symbol of its atomic weapons program.

The communist nation prepared to blow it up Friday in front of diplomats and TV cameras in a dramatic gesture of its commitment to stop making plutonium for atomic weapons.

The demolition at the Yongbyon nuclear complex comes in response to concessions from the U.S., after the North delivered a declaration Thursday of its atomic programs under an agreement at international arms talks with the U.S., China, Russia, South Korea and Japan.

• Bush Offers Carrots for North Korea Nukes Declaration

The North has some immediate incentives to stay in Washington's good graces. President Bush said he would lift economic sanctions imposed under a U.S. law banning trade with enemy nations and said he would notify Congress that the U.S. would remove North Korea from a State Department list of terrorism-sponsoring countries in 45 days.

The energy-starved country is also receiving the equivalent of 1 million tons of heavy fuel oil for the initial disarmament steps.

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"If North Korea continues to make the right choices, it can repair its relationship with the international community. ... If North Korea makes the wrong choices, the United States and its partners in the six-party talks will act accordingly," Bush said.

North Korea faces the worst food shortages in years due to severe floods that devastated farmland in 2007. It has relied on foreign handouts to feed its population since mismanagement and natural disasters devastated its economy in the mid-1990s. As many as 2 million people are estimated to have died of famine then.

• TRANSCRIPT: Bush Discusses North Korean Nuclear Announcement

The North's goodwill could also overcome obstacles to delivery of Washington's promised food aid of 500,000 tons and encourage other nations to join in providing humanitarian assistance to the communist nation, analysts said. The World Food Program says the first shipment of the U.S. food aid is supposed to arrive in Pyongyang this week, although food is not part of the sanctions or nuclear negotiations.

North Korea shocked the world on Oct. 9, 2006, by detonating a nuclear bomb in an underground test to confirm its status as an atomic power. The nuclear blast spurred an about-face in the U.S. hard-line policy that has led the North to take the first steps to scale back nuclear weapons development since the reactor became operational in 1986.

Last year, the North switched off the reactor at Yongbyon, some 60 miles north of the capital of Pyongyang, and it has already begun disabling the facility under watch of U.S. experts so that it cannot easily be restarted.

The destruction of the cooling tower, which carries off waste heat to the atmosphere, is another step forward but not the most technically significant, because it is a simple piece of equipment that would be easy to rebuild.

Still, the blast offers the most photogenic moment yet in the disarmament negotiations that have dragged on for more than five years and suffered repeated deadlocks and delays. Those in attendance include the top State Department expert on the Koreas, Sung Kim, along with broadcasters from the U.S., China, Japan, Russia and South Korea.

In the past, analysts have looked at satellite photographs of the cooling tower to check if steam was rising, the easiest way from outside the secretive country to determine if the reactor was functioning.

Still, many questions remain unanswered and other countries acknowledged they were still far from the goal of disarming the North.

The chief negotiators from the six-party talks will seek some answers as they meet in Beijing, possibly as early as Monday, to discuss specifics on how the North's declaration will be verified. And possibly in July, the highest-level contact between the U.S. and the North since 2000 may take place at a meeting of the foreign ministers of the six nations, including Secretary of State Condoleezza Rice and her North Korean counterpart.

North Korea's nuclear declaration, which was delivered six months later than the country promised and has not yet been released publicly, is said to only give the overall figure for how much plutonium was produced at Yongbyon but no details of bombs that may have been made.

The declaration was being distributed Friday by China, which chairs the arms talks, to the other countries involved, U.S. envoy Christopher Hill said in Kyoto, Japan.

"We'll have to study it very carefully and then we'll have to work on verification," Hill said.

Experts say the North is believed to have as much as 110 pounds of weapons-grade plutonium, which could be used to build as many as 10 nuclear bombs.

To verify the claim of how much radioactive material it has produced, the U.S. says the North will open access to its reactor for inspectors to pore over the aging equipment and come to their own conclusions. However, there will be no wide-ranging inspections of the country to survey secret nuclear facilities, some of which are believed to be hidden in underground tunnels that the North excels at digging.

North Korea now views its reactor as "just large pieces of rusting metal," having already amassed enough nuclear weapons to deter any would-be attacker, said Andrei Lankov, an expert on the North who studied there and is a professor at Seoul's Kookmin University.

"For the dual purposes of blackmail and security, it's sufficient to have a small number of nuclear devices," he said.

Lankov said the North Koreans will likely never come entirely clean on its bombs.

"They know that without nuclear weapons, nobody will care about them," he said.