Theresa May told British troops she would face down Vladimir Putin
She said: "While we are leaving the European Union, as I have said many times, we are not leaving Europe so the United Kingdom is unconditionally committed to maintaining Europe's security.
"Russia's continued aggression represents a growing danger to our friends here in Estonia as well as Latvia, Lithuania and Poland, and our response must be clear and unequivocal.
"By stepping up Nato's deterrence and defence posture you are showing that we are equipped to respond to any threat that we face.
"You are showing that we are ready to do so."