washington u.s. defense secretary jim mattis say friday analysis continue north korea recent missile test believe intercontinental ballistic missile icbm pose imminent threat unite state yet show capable threat us right ... still forensics analysis mattis tell reporters pentagon last month north korea say successfully test new type icbm could reach u.s. mainland south korea u.s.-based experts say data nov. 29 test appear support mattis elaborate lack test show capable threat say immediately test missile go high previous north korean launch part research development effort continue build ballistic missiles threaten everywhere world basically u.s.-based experts skeptical past north korean claim say last month data photos test appear confirm north korea missile sufficient power deliver nuclear warhead anywhere america experts u.s. officials say question remain whether re-entry vehicle capable protect nuclear warhead speed toward target accuracy guidance systems south korea defense ministry say late test put washington within range pyongyang still need prove master re-entry terminal stage guidance warhead activation u.s. base experts believe north korea could two three test away able declare missile operational u.s. president donald trump vow happen north korean say january final stag develop nuclear weapon capable reach unite state trump say options table include military ones although administration make clear prefer diplomatic solution continue diplomatically lead effort mattis say ready conversations ... dialogues president secretary state u.n. security council session crisis friday secretary state rex tillerson urge north korea carry sustain cessation weapons test allow two countries hold talk mattis say north korean icbm yet 'capable threat u.s