Russian Yars ballistic nuclear missiles on mobile launchers roll through Red Square during the Victory Day military parade rehearsals on May 6, 2018 in Moscow, Russia
Russian Yars ballistic nuclear missiles on mobile launchers roll through Red Square during the Victory Day military parade rehearsals on May 6, 2018 in Moscow, Russia.
  • Putin said Russia will suspend its participation in major nuclear arms control pact with US.
  • Without the New START pact and nuclear arms control, the US and Russia could expand their nuclear arsenals.
  • The situation is "bad and could and probably will get worse," one UN researcher said in response. 

Russian President Vladimir Putin announced on Tuesday that Russia will suspend its participation in the New START Treaty, the last major nuclear arms control pact between the US and Russia.