moscow russia retaliate unite state row treaty allow state conduct military observation flight territory russia deputy foreign minister say russian news agencies report wednesday late sign escalate tensions two countries unite state accuse russia flout so-called open sky treaty agreement design build confidence two countries militaries say plan take measure moscow wall street journal newspaper report tuesday would include restrict russian military flight american territory response say moscow prevent u.s. observation flight heavily militarize baltic exclave kaliningrad russian news agencies cite russian deputy foreign minister sergei ryabkov wednesday say moscow unhappy washington compliance treaty would take measure unite state response new u.s. restrictions doubt russian response agencies cite ryabkov tell reporters announce something analyze situation military look respond americans ryabkov quote describe washington approach disagreement one-sided say russia would yield u.s. pressure make concessions u.s. marine general joseph dunford chairman military joint chiefs staff tell senate arm service committee tuesday washington believe would best open sky treaty russia continue place moscow flout russia retaliate u.s. military observation flight row agencies