Seoul - North Korea appears to be preparing to launch a rocket, the US-Korea Institute said on Friday.

The preparations have progressed far enough to mean that a launch could take place as early as the end of next week, according to the 38 North website, which is run by the US-Korea Institute at Johns Hopkins University.

The information was gleaned from satellite photos of the Sohae launch pad located on the west coast of North Korea.

The first two stages of the Unha rocket - also know as Taepodong-2 - were seen on a trailer near the assembly building, the report said.

The website specialises in the analysis of the isolated communist country.

This week the US company DigitalGlobe said the type of activity matched preparations observed before North Korea unsuccessfully launched a rocket in April.

Pyongyang said the April launch was to place a satellite in orbit, but the United States and its allies condemned it as a disguised ballistic missile test, in violation of UN Security Council resolutions.