U.S. President Barack Obama pressed Iranian President Hassan Rouhani today over the detention of three Americans in Iran, including one-time game developer Amir Hekmati, who has been jailed on espionage charges since late 2011. The discussion occurred over the phone during a conversation that largely focused on the status of Iran's nuclear program. It was the first time presidents of the two nations spoke since 1979 and may lay the groundwork for improved relations between the two countries.