territory that you mentioned, you have to know, they were placing their shooting systems and firing those missiles themselves. everybody must know that if we are pressing a corner, on our territory, we will respond the way we can. >> nbc's richard engel is in ukraine with more on that strike. >> russian officials say ukraine took the war to russia, launching a cross border attack with to combat helicopters. this video appears to show their tracer rounds destroying a fuel depot, 20 miles from the ukrainian border. a senior u.s. defense official tells nbc news that ukraine was responsible for the daring raid, ukraine's first of the war. ukraine's official response seemed deliberately ambiguous, with defensive issues saying