North Korea’s rocket launch this month showed it has likely developed technology, long suspected in the West, to fire a warhead more than 10,000 kilometres, South Korean military officials said on Sunday, putting the US West Coast in range. North Korea said the Dec. 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 analysed parts of the first-stage rocket that dropped in the waters off its west coast. “As a result of analysing 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 500-600kgs,” a South Korean Defence Ministry official told a news briefing.