It wants the United States to resume aid and to recognise it diplomatically, although the April launch scuppered a planned food deal.

The North is believed to be some years away from developing a functioning nuclear warhead although it may have enough plutonium for about half a dozen nuclear bombs, according to nuclear experts.

It has also been enriching uranium, which would give it a second path to nuclear weapons as it sits on big natural uranium reserves.

“A successful launch puts North Korea closer to the capability to deploy a weaponised missile,” said Denny Roy, a senior fellow at the East-West Center in Hawaii.

“But this would still require fitting a weapon to the missile and ensuring a reasonable degree of accuracy. The North Koreans probably do not yet have a nuclear weapon small enough for a missile to carry.”

The North says its work is part of a civil nuclear programme although it has also boasted of it being a “nuclear weapons power”.