washington/moscow unite state announce sanction two north korea prominent officials behind ballistic missile program tuesday russia reiterate offer mediate ease tension washington pyongyang new u.s. step late campaign aim force north korea defy years multilateral bilateral sanction abandon weapons program aim develop nuclear-tipped missiles capable hit unite state treasury target leaders north korea ballistic missile program part maximum pressure campaign isolate north korea achieve fully denuclearized korean peninsula treasury secretary steven mnuchin say statement move follow new unite nations sanction announce last friday response north korea nov. 29 test icbm pyongyang say put u.s. mainland within range nuclear weapons sanction seek limit north korea access refine petroleum products crude oil earn workers abroad north korea declare u.n. step act war tantamount complete economic blockade standoff unite state north korea raise fear new conflict korean peninsula remain technical state war since 1950-53 korean war end armistice peace treaty unite state say options include military ones table deal north korea say prefer diplomatic solution north korea give indication will discuss denuclearization u.s. treasury name target officials kim jong sik ri pyong chol say kim reportedly major figure north korea efforts switch missile program liquid solid fuel ri report key official intercontinental ballistic missile icbm development largely symbolic step block property interest two might within u.s. jurisdiction prohibit deal u.s. citizens rule workers party military scientific credentials men two three top experts consider indispensable north korea rapidly develop weapons program photograph television footage show men clearly among north korean leader kim jong un favorites behavior sharply variance obsequiousness senior aid bow hold hand mouth speak young leader ri one prominent aid likely represent workers party missile program experts say bear 1948 ri partly educate russia promote kim jong un start rise rank late 2000s ri visit china russia twice meet china defense minister 2008 air force commander accompany kim jong il visit russian fighter jet factory 2011 accord state media kim jong sik prominent rocket scientist rise play role north korea first successful launch rocket 2012. start career civilian aeronautics technician wear uniform military general munition industry department accord experts south korean government many detail include age know tuesday kremlin long call unite state north korea negotiate say ready act mediator two side will play role russia readiness clear way de-escalation obvious kremlin spokesman dmitry peskov tell reporters ask comment offer spokesman u.s. state department justin higgins say unite state ability communicate north korea variety diplomatic channel add want north korean regime understand different path choose however north korea change course return credible negotiations russian foreign minister sergei lavrov make similar offer monday tell u.s. secretary state rex tillerson phone call tuesday washington aggressive rhetoric beef military presence region heighten tension unacceptable ministry say lavrov underscore need fast move negotiate process language sanction say another u.s. state department spokesman michael cavey say washington remain open talk onus north korea take sincere meaningful action toward denuclearization refrain provocations south korea unification ministry forecast tuesday north korea would look open negotiations unite state next year continue seek recognition de facto nuclear power unite state stress need countries especially russia china north korea main trade partner fully implement sanction include cut oil supply accord chinese customs data china export oil products north korea november apparently go beyond u.n. sanction impose early year china also import north korean iron ore coal lead november second full month trade sanction data show china disclose crude export north korea several years industry source say still supply 520,000 tonnes 3.8 million barrel year country via age pipeline north korea also source oil russia trade north korea china slow year particularly china ban coal purchase february chinese export corn north korea november also slump 82 percent year early 100 tonnes low since january export rice plunge 64 percent 672 tonnes low since march u.s. sanction north korean missile experts russia offer mediate