This month's rocket launch by reclusive North Korea shows it has likely developed the technology, long suspected in the West, to fire a warhead more than 10,000 km (6,200 miles), South Korean officials said on Sunday, Dec 23, putting the U.S. West Coast in range, Reuters reported.

North Korea said the December 12 launch put a weather satellite in orbit but critics say it was aimed at nurturing the kind of technology needed to mount a nuclear warhead on a long-range missile.

North Korea is banned from testing missile or nuclear technology under UN sanctions imposed after its 2006 and 2009 nuclear weapons tests and the UN Security Council condemned the launch.

South Korea retrieved and analyzed parts of the first-stage rocket that dropped in the waters off its west coast

"As a result of analyzing the material of Unha-3 (North Korea's rocket), we judged North Korea had secured a range of more than 10,000 km in case the warhead is 500-600 kg," a South Korean Defense Ministry official told a news briefing.

North Korea's previous missile tests ended in failure.