North Korea has announced an imminent rocket launch in a move sure to draw stern US and UN condemnation and rack up tensions with South Korea which is just days from a presidential election.

It will be the North's second long-range rocket launch this year following a much-hyped but failed attempt in April.

In a statement carried by the Korean Central News Agency (KCNA), the Korean Committee for Space Technology said the new bid would be carried out between December 10 and 22.

The South Korean foreign ministry condemned the planned launch as a "deeply provocative act" that defied UN resolutions and would have significant repercussions for the already isolated state.

As in April, the North said it would be a purely "peaceful, scientific" mission aimed at placing a polar-orbiting earth observation satellite into orbit.

The US and its allies insist the launches are disguised tests for an inter-continental ballistic missile (ICBM) capable of carrying a nuclear warhead.

As such they would contravene UN resolutions triggered by Pyongyang's two nuclear tests in 2006 and 2009.

They say the North's Unha-3 rocket is actually a three-stage variant of the Taepodong-2 ICBM that Pyongyang has been developing for years but has never tested successfully.

Saturday's announcement ended weeks of intense speculation, based on satellite image analysis, that the North was preparing a fresh launch from its Sohae satellite launch station.

South Korea had repeatedly warned in recent months that the North would seek to destabilise the situation on the Korean peninsula ahead of the South's presidential election on December 19.

"We sternly warn if the North goes ahead with the launch, it will face strong countermeasures from the international community," South Korea's foreign ministry statement said.

On Thursday the UN Security Council had warned Pyongyang that going ahead with another launch would be "extremely inadvisable".

AFP