The spokesman said, "That decision to not take questions was not made today or yesterday and has nothing to do with the situation at the United Nations," referring to Brazil's bid to be assigned a permanent seat on the U.N. Security Council, The New York Times reported.
Instead of a press conference with the two presidents fielding questions, each leader would be allotted to time to make statements after the meeting.
Reporters had expected a press conference, which was listed in White House itineraries for the trip.
A senior White House official said, "These things are the host country's call."
President Obama and members of his immediate family, including his wife Michelle, his daughters Sasha and Malia, his mother-in-law Marian Robinson and his daughters' godmother Eleanor Kaye Wilson, arrived in Brazilia early Saturday morning after an all-night flight from Washington.