North Korea vowed Wednesday to continue its space programme despite international outrage after it launched a long-range rocket, saying it was not a matter of debate for the United Nations Security Council.

"No matter what others say, we will continue to exercise our legitimate right to launch satellites," a foreign ministry spokesman said in a statement carried by the North's official Korean Central News Agency.

He urged the international community to "use reason and remain cool so as to prevent the situation from developing (in an) undesirable direction".

The North's rocket launch intensified the threat posed by the nuclear-armed state and provoked global condemnation.

It triggered plans for an emergency session of the UN Security Council (UNSC), which has imposed round after round of sanctions against North Korea over its ballistic missile and nuclear programmes, to little avail.

The UNSC said it would meet Wednesday, with one Western diplomat predicting a "strong response".

The North's spokesman insisted Wednesday's launch was "part of peaceful work in line with the country's scientific and technological development plan for the economic construction and improvement of people's living standard".

"Hostile forces... are showing signs of (a) sinister bid to take issue with the launch for peaceful purposes, while terming it 'violation of resolution' of the UN Security Council," he said.

"The right to use outer space for peaceful purposes is universally recognized by international law and it reflects the unanimous will of the international community. So this issue is not one over which the UNSC can say this or that," he said.

The spokesman added that Washington had over-reacted to the previous rocket launch in April "out of hostile feelings which compelled (North Korea) to reexamine the nuclear issue as a whole".

"The concept of hostility will not be of any help, and confrontation will not help settle anything, either," he said.