Football's governing body didn't elaborate on Thursday when "We Are One (Ole Ola)" will be released.
Written and co-produced by Pitbull, the song "is set to bring the passion of Brazil to the world" and "ignite the excitement felt by football fans" for the tournament kicking off in June.
Leitte says she is looking forward to "dancing samba with Pitbull and Jennifer Lopez in Brazil."
Lopez was not in Rio for the announcement.
Shakira wrote "Waka Waka" for the 2010 World Cup in South Africa.