The Stars and Stripes need a draw in their final Group G match against Germany in Recife on Thursday to qualify for the knockout stages of the competition.
The Americans could have secured qualification with a game to spare on Sunday but were denied when Silvestre Varela's diving header earned Portugal a late 2-2 draw in Manaus.
Despite the disappointment of failing to hold on for the win against Paulo Bento’s side, Klinsmann believes his team will use the support they get from fans to get a result against his own nation, Germany.
"The fans' support for us is overwhelming, it's unbelievable," he told US Soccer's official YouTube channel.
"When we go and take the bus to the stadium and see thousands of US fans streaming towards the stadium chanting it gives us that extra amount of energy that we need.
"We need now all the energy from the fans going to Recife, being loud and pushing for us.
"Seeing the pictures from home, suddenly people are really into soccer and supporting our team and we feel that and get that energy and we'll take that into the game. It helps a lot.
"It makes you feel accountable and responsible for giving everything you have on the field in every World Cup game.
"You have to be in there and take that energy to another level against Germany."
Jozy Altidore is set to miss out on the clash against Joachim Low’s side with a hamstring injury, which he sustained during the win over Ghana, but defender Matt Besler will be available after recovering from a similar problem.