The first international phone call occurred on December 25, 1900 when John Atkins, manager of the Key West office of the International Ocean Telegraph Company, called Havana, Cuba. They were testing to see if telegraph wires could carry a human voice transmission. Finally, the first words spoken came from Cuba. "I don't understand you" were the words.
In 1921, AT&T connected Havana and New York with deep sea cables. The first person to receive an international phone call from an American president was Cuban President Mario Garcio Menocal. Herbert Hoover called him on April 11, 1921. The price for the first three minutes of the call was $13.65.
By 1927, international calls were available between the United States and London using a radio. The first three minutes cost $75. Trans-Pacific calls, also using a radio, could be made five years later. The initial three minutes cost $39.
Now called the ITU-T, the International Telegraph Union was originally a specialized agency formed by the United Nations in 1947. Thirteen years later, the International Telegraph and Telephone Consultative Committee (CCITT) was created and released it's first Red Book of European country codes. The ITU-T continues to monitor standards and practices of all international telecommunication practices.