North Korea is preparing for fifth nuclear test, South Korea's spy agency said on Sunday.

South Korea's spy agency also said that North Korea has technology for intercontinental ballistic missiles.

The UN Security Council called an emergency meeting on Sunday, after North Korea's launch of a long-range rocket, which Pyongyang said was carrying a satellite, but the US and its allies condemned as a missile test.

US Strategic Command said Sunday that its "systems detected and tracked what we assess was a North Korean missile launch into space ... the missile was tracked on a southerly launch over the Yellow Sea."

Pyongyang pronounced the mission a "complete success," after claiming the rocket managed to put an observation satellite into orbit

State-run KCNA news agency showed a photograph of North Korean leader Kim Jong Un signing the order for the launch of the satellite, Kwangmyongsong-4.