The Americans were written off as contenders to qualify from Group G, which also contained Cristiano Ronaldo's Portugal and African giants Ghana.

But a win over Ghana and a draw with Portugal meant they defied the odds to reach the next round on goal difference.

"It's huge getting out of this group," said Klinsmann.

"Everybody said 'You have no chance' but we took our chance and now we move on and we really want to prove a point."

The former Germany coach praised the contribution of goalkeeper Tim Howard, a towering presence at the back for most of the game who was beaten only by a superb Thomas Mueller long-range strike.

"Tim is one of our big shots. He's our leader, he keeps everyone together and obviously we need him right now," Klinsmann said of the Everton stopper.

"In a World Cup if you want to go far you need one of the best goalkeepers in the world -- and we have one."

Germany will now play the winner of Group H in the last 16, expected to be Belgium, in Salvador next Tuesday.

But Klinsmann said he believed his team could raise their game again.

"We can still do better. We got through the group but we can do better in the round of 16 and we will do better," he said.

Goalkeeper Howard meanwhile tipped Germany to be one of the contenders for the title.

"Hats off to Germany - I think they have an opportunity to win the World Cup, that's how good I think they are," Howard said.