washington russia test president donald trump surge violence eastern ukraine u.s. president give ukraine lethal aid need defend attack senator john mccain say letter trump thursday renew violence flare week moscow-backed rebel ukraine government force cause high casualty rate since mid-december cut power water thousands civilians side frontline surge attack begin day talk phone clear indication vladimir putin move quickly test commander chief america response last consequences mccain say letter trump release office washington supply aid ukraine include drone radar first-aid kit night vision communications gear part democratic president barack obama strategy provide non-lethal military assistance focus sanction diplomacy end war election trump whose call good relations moscow alarm kiev conflict remain unresolved lawmakers washington express support ukraine thursday call restraint moscow mccain urge trump use authority exist defense policy law provide lethal assistance ukraine vladimir putin violent campaign destabilize dismember sovereign nation ukraine stop unless meet strong determine response mccain write mccain also urge trump expand current sanction russia put place annexation ukraine crimea region 2014. democratic senator ben cardin top democrat senate foreign relations committee say would work mccain senators codify exist sanction law incumbent upon senate clearly express support sovereignty ukrainian solidarity close ally europe say nancy pelosi top democrat house representatives also caution trump administration thursday ease sanction moscow say move would staggeringly dangerous wednesday nato secretary general jens stoltenberg call russia use considerable influence separatist rebel end violence bring fester conflict back focus amid warn loom humanitarian crisis freeze winter temperatures mccain say russia test u.s. ukraine urge trump hit back