North Korea has agreed to suspend its nuclear activities and accept a moratorium on nuclear and long-range missile tests, according to the US.

The breakthrough came after lengthy negotiations. North Korea adopted a more amenable position after the death of Kim Jung-il in Decmber.

The move prompted speculations North Korea would try to reactivate the multi-nation disarmament-for-aid talks it left in 2009.

State Department spokeswoman Victoria Nuland said North Korea had agreed to allow inspectors from the International Atomic Energy (IAEA) to verify and monitor the moratorium on uranium enrichment and confirm disablement of its nuclear reactor at Yongbyon, AP reported.

A meeting would be held to finalise the agreement which will provide up to 240,000 tonnes of food aid to the hermit nation.

A spokesman for North Korea's foreign ministry confirmed the breakthrough and said it reflected a "positive atmosphere".

"The United States still has profound concerns regarding North Korean behaviour across a wide range of areas but [the] announcement reflects important, if limited, progress in addressing some of these," Nuland said.