516a608ae0edfd158c72643ecd03769ca2a694a2South Korea’s defence ministry said Tuesday that North Korea appeared to have achieved a “significant” level of technology to miniaturise a nuclear device to be fitted on the tip of a missile. The ministry made the warning in a white paper due to be released later Tuesday, although defence officials said the nuclear-armed North has yet to demonstrate its miniaturisation capacity. “North Korea’s capabilities of miniaturising nuclear weapons appear to have reached a significant level,” the ministry said in a statement. Pyongyang has conducted three nuclear tests, most recently in February 2013. The defence ministry said the North had probably secured some 40 kilos (88 pounds) of weapons-grade plutonium by reprocessing spent nuclear fuel rods, and that it is working on a highly enriched uranium programme. Pyongyang mothballed the five-megawatt reactor at its main Yongbyon nuclear complex in 2007 under an aid-for-disarmament accord, but began renovating it in mid-2013. The facility is the country’s main source of weapons grade plutonium. More