kiev u.s. defense secretary jim mattis visit ukraine thursday say washington would keep pressure russia call aggressive behavior signal personal support provide weapons kiev mattis say russia abide minsk ceasefire agreement mean end separatist conflict eastern ukraine unite state would maintain sanction moscow despite russia denials know seek redraw international border force undermine sovereign free nations europe mattis tell reporters alongside ukrainian president petro poroshenko mattis visit time ukrainian independence day second high-profile show u.s. support many months u.s. secretary state rex tillerson come kiev july ukraine count u.s. support russia since pro-western government take power follow street protest 2014 kremlin-backed president flee country president donald trump comment election campaign last year appear recognize crimea part russia stoke fear kiev trump might mend tie moscow ukraine expense emphasize trump yet take decision issue mattis signal personal support longstanding ukrainian request defensive weapons could include anti-tank javelin missiles anti-aircaft systems mattis also play fear voice previous white house administration barack obama supply weapons could escalate situation defensive lethal weapons actively review go back see current situation able inform secretary state president specific term recommend direction ahead mattis say defensive weapons provocative unless aggressor clearly ukraine aggressor since territory fight happen mattis say poroshenko say satisfy progress discussions weapons also say mattis discuss possibility u.n.-backed arm force send eastern ukraine relations ukraine russia go freefall moscow annexation crimea 2014 subsequent outbreak kremlin-backed separatist insurgency eastern ukraine kill 10,000 people russia deny send troop weapons eastern ukraine accord u.s. officials plan provide defensive weapons ukraine make way white house sign thus far pentagon say provide 750 million non-lethal aid ukraine since 2015 include radars uniform supply weapons huge boost support ukraine say michael carpenter former deputy assistant secretary defense region carpenter say weapons discussion effectively use take territory mean provide would help stabilize situation u.s. senator john mccain chairman senate arm service committee also press trump administration act secretary mattis visit kiev provide yet another opportunity unite state correct policy toward ukraine provide lethal defensive assistance country need defend sovereignty territorial integrity mccain say statement wednesday mattis strong word moscow thursday likely reassure eastern european ally concern russia military activity region include plan war game september russia belarus aim hold joint exercise north atlantic treaty organization ally believe could number 100,000 troop involve nuclear weapons train big exercise since 2013. early year estonia defense minister say russia may use exercise move thousands troop permanently belarus warn nato russia dismiss western worry war game buffoonery defense secretary mattis promise support ukraine say review lethal aid