United States coach Jurgen Klinsmann on Monday questioned the validity of appointing a referee from Algeria for his team's World Cup last 16 clash with Belgium.

"This Algerian referee (Djamel Haimoudi) is able to speak French with their (Belgium) players on the field and not with us," the German told a press conference on the eve of Tuesday's game in Salvador.

"And it's a country (Algeria) that we beat in the last second in the last World Cup," added Klinsmann, who was not coach then and took over in 2011 from Bob Bradley.

"I understand it's difficult for FIFA to choose the right referees for the right games and it has always been tricky for FIFA, but it is what it is.

"We give it the benefit of the doubt, we respect the decision and hope that everything goes well."

The 43-year-old Haimoudi has already taken charge of Australia's 3-2 defeat to the Netherlands on June 18 and the goalless draw between Costa Rica and England six days later.

We hope it's not a concern," Klinsmann stated.

"We know that already he did two games very well so we hope he continues that tomorrow."