North Korea has almost completed preparations for a third nuclear test, a senior source with close ties to Pyongyang and Beijing told Reuters, which will draw further international condemnation following a failed rocket launch if it goes ahead.The isolated and impoverished state sacrificed the chance of closer ties with the United States when it launched the long-range rocket on April 13 and was censured by the U.N. Security Council, including the North’s sole major ally, China.Critics say the rocket launch was aimed at honing the North’s ability to develop an intercontinental ballistic missile capable of hitting the United States, a move that would dramatically increase its military and diplomatic heft.Now the North appears to be about to carry out a third nuclear test after two in 2006 and 2009."Soon. Preparations are almost complete,” the source said when asked whether North Korea was planning to conduct a nuclear test.This is the first time a senior official has confirmed the planned test and the source has correctly predicted events in the past, telling Reuters about the 2006 test days before it happened.The rocket launch and nuclear test come as Kim Jong-un, the third of his line to rule North Korea, seeks to cement his grip on power.Kim took office in December and has lauded the country’s military might, reaffirming his father’s "military first” policies that have stunted economic development and appearing to dash slim hopes of an opening to the outside world.Washington, Seoul and Tokyo, which have most to fear from any North Korean nuclear threat, are watching events anxiously and many observers say that Pyongyang may have the capacity to conduct a test using highly enriched uranium for the first time.Defense experts say that by successfully enriching uranium, to make bombs of the type dropped on Hiroshima nearly 70 years ago, the North would be able to significantly build up stocks of weapons-grade nuclear material.