The UN security council will begin behind-the-scenes negotiations today designed to strengthen sanctions against North Korea after the communist state appeared to have successfully tested a nuclear weapon as powerful as the one that destroyed Hiroshima. With the 15-member council called to an emergency session last night, diplomats scrambled to forge a unified front against the test which was seen as a provocative step towards North Korea gaining a full nuclear arsenal. Early this morning it was reported that North Korea is ready to test another missile. Yonhap news agency quoted a South Korean official as saying that North Korea will fire another short-range missile off its west coast either later today or on Wednesday. Barack Obama spoke at the White House, denouncing North Korea’s action as “a blatant violation of international law”. He said North Korea “will not find security and respect through threats and illegal weapons”. Japan, which considers itself high on Pyongyang’s potential hit list, said it would seek a fresh UN resolution condemning the test. Gordon Brown described the test as “erroneous, misguided and a danger to the world”. Closed door talks at the UN security council in New York produced no fresh initiative last night…