Biden flew to the northeast Brazilian city of Natal to watch the match at the start of a four-country Latin American tour.
Security reasons held up his motorcade from the airport until just after kick-off. Biden missed Clint Dempsey's goal 30 seconds into the game. The goal was the fastest of this World Cup and one of the quickest in the tournament's history.
The United States went on to win the Group G match 2-1.
Biden will meet with President Dilma Rousseff Tuesday, looking to patch up relations strained by revelations of US spying on her personal phone and email communications, before traveling on to Colombia, Dominican Republic and Guatemala.