Belgium coach Marc Wilmots expects a physical United States side to throw all they have at his team in the last 16 of the World Cup.
"Physically they are very strong. We are preparing for a war," said Wilmots, whose side have won four out of the five previous meetings between the two.
This includes a 4-2 victory over the USA in May last year.
"We cannot compare this game to the friendly last year. Besides we are playing a knockout match which is completely different," said attacking midfielder Kevin de Bruyne.
Belgium's best World Cup outing was reaching the semi-finals in Mexico in 1986.