tokyo unite state respond strongly case north korean nuclear test u.s. deputy secretary state antony blinken say monday days north failure launch unite state believe intermediate-range ballistic missile north korea conduct fourth nuclear test january long-range rocket launch next month contravention u.n. security council resolutions expand u.n. sanction aim starve north korea fund nuclear weapons program approve unanimous security council vote early march resolution draft unite state china blinken meet senior japanese government officials tokyo tell reporters north korea would dig deep hole pursue provocations additional strong response case another north korean nuclear test blinken say add action north korea unacceptable blinken say unite state would consider number possibilities add premature specific experts expect north korea conduct fifth nuclear test near future possibly party congress early may follow embarrass missile failure friday u.s. pledge 'strong response event another north korean nuclear test