South Korea has also welcomed the deal as a step toward establishing a permanent peace on the Korean peninsula.
Roh Moo-hyun, the South Korean president, said the agreement was "very detailed and well-made", adding that "both sides have shown sincerity".
A clause included in the deal calls for a separate forum to negotiate a formal peace treaty between North and South Korea, replacing the uneasy ceasefire that has been in place since the end of the Korean War in 1953.
But in a possible indication of problems to come North Korea's state media has referred to the "temporary suspension" of its nuclear facilities under the deal.
In a brief report on the agreement, the North's official KCNA news agency said the five other parties involved in the talks had offered economic and energy aid "in connection with [North Korea's] temporary suspension of the operation of its nuclear facilities."
Earlier Condoleezza Rice, the US secretary of state, described the agreement with North Korea as "a good beginning" but said it was "not the end of the story".
"The goal is the complete, verifiable and irreversible denuclearisation of the Korean peninsula," she said.
'Message to Iran'
Rice rejected suggestions from some, including the former US ambassador to the UN, John Bolton, that the deal would be seen as rewarding bad behaviour by nations such as Iran.
|The deal says North Korea must allow |
international inspectors to return [EPA/KCNA]
Iran is also under US pressure over its nuclear programme, which Tehran insists is entirely for peaceful purposes.
"Why shouldn't it be seen as a message to Iran that the international community is able to bring together its resources," Rice said.
"It's a good story of international cooperation and of bringing together the right states to bring together the right set of incentives and disincentives."
Rice insisted that under the deal North Korea was implicitly bound to give up its nuclear arsenal.
"The joint statement covers the fact that North Korea must declare and abandon all of its nuclear programs, and everybody understands what 'all' means," she said.
|US envoy Christopher Hill says much |
work remains to be done [Reuters]
The deal, agreed after days of intense negotiations at six-nation talks, requires North Korea within 60 days to shut down and seal "for the purpose of eventual abandonment" its main nuclear facility at Yongbyon.
It must also readmit UN nuclear inspectors to verify the process. In return North Korea will receive aid in the form of fuel oil or equivalent to help supply its energy needs.
The deal however does not address what happens to North Korea's existing nuclear weapons – thought by some to number around six or more – or what happens to the country's existing stock of fissile nuclear material, suitable for use in weapons.
The International Atomic Energy Agency (IAEA), the UN's nuclear watchdog, said on Tuesday it was ready to authorise inspectors to return to North Korea.
Officials said equipment had already been prepared and a team was ready to leave "at short notice".
Mohamed ElBaradei, the IAEA chief, said the North Korean move was "a step in the right direction".
North Korea expelled IAEA inspectors four years ago after being accused by the US of seeking to develop a nuclear bomb. It then withdrew from the Nuclear Non-Proliferation Treaty.
Commenting on the deal, Christopher Hill, the chief US envoy to the talks, said that much difficult work remained and there were "some ambitious time schedules" ahead.
"I think we all need a rest in the next 24 hours, but we have so much work to do," Hill told reporters before leaving Beijing on Wednesday.
He said the talks had almost broken down without agreement but a marathon negotiating session late on Monday had reached a compromise on the amount of energy aid the other five parties were prepared to offer North Korea.
The talks brought together envoys from the US, China, Russia, Japan as well as the two Koreas.
"It was the energy issue, and it was our willingness to go bigger on energy in return for them going deeper on denuclearisation," Hill said.
The agreement also includes provisions for the United States and Japan to discuss normalising diplomatic ties with North Korea, and says Washington will begin the process of removing Pyongyang from its list of state sponsors of terrorism.
"We have to start a process on that," Hill said.
"Some of it is legal, some of it's political, some of it's diplomatic, and some of it is just related to the basic proposition that when they get out of this nuclear business, everything will be possible and if they don't get out of the nuclear business, nothing is possible."