North Korea has agreed to disable its Yongbyon reactor and provide a complete declaration of all nuclear programmes by the end of the year.
In an agreement which won praise from US President George W Bush, the isolated state will in return get aid equivalent to 1 million tonnes of heavy fuel oil and the United States will move towards taking it off a terrorism blacklist.
The United States will lead an expert group to North Korea within the next two weeks to prepare for the disabling of the country's nuclear facilities, according to a statement agreed at six-party disarmament talks.
The talks, aimed at ending Pyongyang's nuclear programmes ended on Sunday to allow delegates to return to their home countries to discuss a joint statement with their governments.
The deal was released in Beijing today after all parties - the two Koreas, the US, Japan, Russia and China - had signed off on it.
"The DPRK agreed to provide a complete and correct declaration of all its nuclear programmes ... by 31 December 2007," the statement said.
Japan also hailed the agreement but there may yet be problems with implementation.
North Korea has repeatedly demanded that in return for disarmament other countries must commit to completing two light-water reactors left partly built when a previous disarmament deal fell apart at the end of 2002.
Producing plutonium for weapons is much more difficult with light-water reactors but the international community have been reluctant to leave North Korea with any nuclear capability.
Hajime Izumi, Korea expert at the University of Shizuoka near Tokyo, said the deal marked encouraging, if modest, progress.
"This is an important step in the right direction towards denuclearisation of the Korean peninsula [but] there is still a long way to go," he said.
North Korea also reaffirmed its commitment not to transfer nuclear materials, technology or know-how, the statement added.
But it skirted around the issue of when the country would be removed from a US terrorism blacklist - one of Pyongyang's key demands - saying only that Washington would fulfil its commitments to begin the process, in parallel with action on the ground.