Chicago , Madrid , Tokyo , Rio de Janeiro are finalists to host 2016 Summer Olympics . Comment: Obama trip to Denmark marks first time a U.S. president has attended IOC vote . The United States has hosted four Summer Olympic Games . On one-day trip , Obama will also meet with Denmark 's queen , prime minister .
Chicago , Madrid , Tokyo , Rio de Janeiro are finalists to host 2016 Summer Olympics . Comment: Obama trip to Denmark marks first time a U.S. president has attended IOC vote . On one-day trip , Obama will also meet with Denmark 's queen , prime minister .