FIFA Secretary General Jerome Valcke (C), U.S. singer Pitbull (L) and Brazilian singer Claudia Leitte attend a press conference after a regular meeting of FIFA Local Organizing Comittee (LOC) in Rio de Janeiro, Brazil, Jan. 23, 2014. FIFA LOC announced here on Thursday that U.S. pop singers Jennifer Lopez, Pitbull and Brazilian singer Claudia Leitte will jointly sing the official theme song "We Are One" for the 2014 FIFA World Cup. (Xinhua/Xu Zijian)