US envoy Christopher Hill hailed an agreement reached at talks on North Korea's nuclear ambitions, calling it a win-win deal, but said the issue of peaceful nuclear energy for North Korea would not be rushed.

"We'll have discussions on the issue of peaceful energy, particularly the subject of provision of a light water nuclear reactor, but only at an appropriate time," he told reporters.

"And that appropriate time is once the DPRK has gotten back to the NPT in good standing and gotten back into the NPT with IAEA (International Atomic Energy Agency) safeguards.

"Talk about the DPRK's right to peaceful use in advance of them is really to talk theory rather than facts."

North Korea's insistence on help from the international community to build light water reactors to generate electricity proved the main sticking point in multinational talks that ended Monday.

Under a now defunct 1994 agreement, two light water reactors were to have been built by a US-led consortium to replace North Korea's existing graphite-moderated reactors which can produce weapons-grade plutonium.

But construction was suspended after the United States in 2002 accused the North of developing a secret uranium-enrichment program. The North responded by throwing out weapons inspectors and leaving the NPT.

The United States, backed by Japan, argues the cost and timeframe of building the reactors is impractical and that the energy-starved state cannot be trusted to confine a reactor to civilian use.

In a joint statement issued at the talks' conclusion, North Korea pledged to give up its nuclear weapons in exchange for promises of aid and security and a return to the NPT.

In return, the other nations agreed to "recognise" its demand for nuclear energy and said Pyongyang's request to have a light water nuclear reactor for peaceful purposes would be revisited later.

Hill called North Korea's decision to abandon its nuclear weapons "a moment which will be very important in their history".

"It is a big decision for them but is absolutely the right decision for them," he said.

The talks will resume in November and establishing a verification regime would take centre stage, he added.

"Verification is very, very important to this agreement," he said.

"I would say that the key element of the November discussions will be the verification regime and clearly this will involve international verification, the IAEA. We'll have to do some early consultation to see how that will work."