However, Klinsmann refused to be downbeat about his team's performance.
He told BBC Sport: "When you concede in the last second it is unfortunate, but it was an amazing game from us, I can't ask for any more. Now we have to get a result against Germany and that is what we are going to do.
"We controlled the game after conceding the early goal and had chances to score three or four goals after coming back. We will take even more confidence into the next game, it will be another final but that is what the World Cup is about.
"We were that close, we didn't quite make it so we have to make it against Germany. We have to move on, analyse a couple of things."
The USA can qualify for round two with a win or draw against Germany on Thursday.