President Obama is in Estonia for talks with Baltic leaders about the crisis in Ukraine.
The leaders of Estonia, Latvia and Lithuania are reportedly concerned about possible Russian aggression following the recent intervention in Ukraine.
Mr Obama will then travel to the Nato summit in south Wales where leaders from the military alliance are expected to support a new rapid-reaction force to respond to any Russian action in eastern Europe.
Were the Russians -as Barack Obama claims - weighed down by sanctions, or where the Ukrainians looking to cut their losses?
The new president of the European Council could be "very important" for David Cameron.