washington u.s. president donald trump sunday dismiss prospect talk north korea waste time day secretary state say unite state maintain open line communication north korean leader kim jong un tell rex tillerson wonderful secretary state waste time try negotiate little rocket man trump write twitter use sarcastic nickname kim seem contradict top u.s. diplomat trump trade insult threats kim recent weeks amid escalate tensions pyongyang nuclear missile program late tweet white house predecessors bill clinton george w. bush barack obama fail north korea nice rocket man would work ask kim succeed father kim jong il north korean leader 2011 obama administration previous presidents negotiate pyongyang ultimately fail prevent press ahead internationally condemn weapons program tillerson disclose saturday unite state directly communicate north korea nuclear missile program pyongyang show interest dialogue save energy rex do trump say tillerson say trip china unite state multiple direct channel communication pyongyang first disclosure trump administration probe north korea see interest dialogue tillerson express hope reduce tensions north korea fast advance toward goal develop nuclear-tipped missile capable hit u.s. mainland probe stay tune tillerson tell small group reporters ask would like talk say unite state couple three channel open pyongyang beijing monday china foreign ministry say support dialogue consistently support unite state north korea engage dialogue contact promote mutual understand resolve relate issue consultations say email response reuters query tillerson revelations contact north korea senior trump administration official ask clarification trump sunday morning tweet play significance communication channel time north korea continue provocations president think time negotiate official say speak condition anonymity extent diplomatic channel exist washington pyongyang aim secure return americans detain north korea official add r.c hammond adviser tillerson deny boss undercut trump tweet reject suggestion secretary state resign let resign idea resignation president make clear kim regime diplomatic offer table cool hammond say twitter also downplay contact channel open months unused cool months hammond write state department spokeswoman heather nauert make similar point sunday diplomatic channel open kimjongun open forever write twitter u.s. representative adam schiff top democrat house representatives intelligence committee write twitter tillerson waste time boss fail understand catastrophic consequences war korean peninsula trump rhetoric north korea run gamut personal attack kim veil military threats denial interest talk insistence would prefer diplomatic solution announce new u.s. sanction north korea last month acknowledge diplomacy still possible ask also frequently declare military options disposal although u.s. officials outside experts long say u.s. strike north korea would risk massive casualties trump top u.s. diplomat n't bother talk north korea