washington unite state see value new start arm control treaty russia despite washington concern moscow track record arm control issue senior u.s. officials say friday remark trump administration officials speak reporters condition anonymity suggest treaty remain force door remain open pursue extension accord set expire 2021. new strategic arm reduction treaty give countries february 2018 reduce deploy strategic nuclear warheads 1,550 low level decades also limit deploy land- submarine-based missiles nuclear-capable bombers reuters report president donald trump first call russian president vladimir putin criticize new start treaty say favor moscow one trump administration officials say friday unite state look discard new start senior u.s. officials include u.s. defense secretary jim mattis question russia reliability arm control cite longstanding u.s. allegations russia violate cold war-era intermediate-range nuclear force inf treaty russia deny treaty violations accuse unite state accusations come amid nosedive u.s.-russian relations u.s. intelligence agencies accuse russia meddle u.s. presidential election moscow deny recent tit-for-tat exchange washington moscow include move slash others diplomatic presence tensions reach syria unite state russia back different force scramble claim leave islamic state-held territory russia warn unite state thursday would target u.s.-backed militias syria russian troop come fire still second senior trump administration official say friday unite state seek ways improve communication moscow build degree trust official describe non-existent trump take office say want improve tie strain since moscow 2014 annexation crimea separatist conflict eastern ukraine lead washington impose sanction russia ukraine petro poroshenko meet trump thursday say afterward share vision new level defense cooperation second senior trump administration official say decision whether provide defensive arm ukraine something kiev long want despite tensions u.s. see value new start treaty russia