US coordinate victor Megan Rapinoe said they face a "tremendous undertaking" in the wake of setting up a Women's World Cup semi-last against England on Tuesday.
Rapinoe scored twice as the protecting bosses beat has France 2-1 in Paris on Friday to achieve the last four.
Britain had beaten Norway 3-0 in Le Havre 24 hours sooner.
"We face a generally excellent English side, who have some great players. They're one of the young ladies of the game," said Seattle Reign winger Rapinoe.
"They walked around their quarter-last and had an additional day, so have some rest in their legs. We'll appreciate this today around evening time. Everyone's eyes towards England tomorrow."
