Russia will open polling stations for its March presidential election at three diplomatic missions in the United States, its envoy in Washington said Wednesday. The announcement came as Moscow said it has not yet decided if voting will take place in what it calls “unfriendly” countries — those which it accuses of carrying out “hostile” actions against Russian missions abroad. Early unconfirmed reports suggested that Moscow could bar its citizens living in those countries from voting at embassy polling stations in the March election, when President Vladimir Putin is widely expected to secure a …