(VOVworld) - Russian President Vladimir Putin phoned US President Barack Obama on Thursday to discuss the Iran nuclear talks, and the need to counter Islamic State militants. This was the first telephone conversation between Putin and Obama since last February. The White House said the two leaders also discussed the increasingly dangerous situation in Syria, where IS militants are operating and underscored the importance of continued P5+1 unity in ongoing negotiations to prevent Iran from acquiring a nuclear weapon. Obama reaffirmed that Russia needs to live up to the terms of the Minsk agreement with Ukraine. The phone conversation took place in the midst of the worst standoff between Russia and the West since the Cold War, triggered by the crisis in Ukraine.