(Reuters) - The future of soccer in the United States has never seemed brighter.

Like the rest of the planet, the land of the free has been swept up in the excitement of the World Cup, with millions of people glued to their television sets watching the events unfold in Brazil.

The enthusiasm for Team USA - one of the tournament's supposed underdogs - has been infectious with President Barack Obama leading a nationwide cheer squad that includes America's biggest sports stars and celebrities.

The World Cup remains one of the few final frontiers that no U.S. team has ever conquered but if the surge of American children who have made soccer their first-choice sport is any indication, it may only be a matter for time.

The U.S. national head coach Juergen Klinsmann knows better than most the enormous potential of the U.S. but for him, the future will have to wait.

"We are not thinking at all about the future right now, we are thinking about the present and we want to go far," he told a news conference on Monday, the eve of his team's second round clash with Belgium.

"The more experienced players like Clint Dempsey, Tim Howard, DaMarcus Beasley, Jermaine Jones, this is the moment, you have to squeeze everything out of yourself.

"Right now it is all about Brazil, this World Cup."

The U.S. were rated as longshots to win the title after being drawn in a difficult group with Germany, Portugal and Ghana, but defied the odds to finish runners-up to Germany and reach the last 16.

The road ahead is no easier with Belgium favored to end America's run as early as Tuesday but Klinsmann, a World Cup winner with Germany in 1990, has instilled his players with the belief that now is their moment.

"We made it out of a difficult group and now every game is 50/50," he said.

"We need to be spot on, right now, give everything we have. I am confident that if every player gets to his limits tomorrow we will have a positive outcome.

"We started a process there years ago, we see a lot of things developing on many fronts, but you know you get judged by how good the outcome is in the World Cup."

Despite sticking to his mantra of living for the moment, Klinsmann has more than a vested interest in the future of American soccer and knows the longterm value of a strong showing by his team in Brazil.

In addition to being the head coach of the national team, he is also the technical director for U.S. Soccer, helping oversee the development of youth teams. His teenage son Jonathan is a member of the national under 18s squad.

Thousands of Americans have traveled to Brazil to watch the World Cup and Klinsmann said the support had given his players an added sense of duty to keep going.

"You see where the game is going in the United States, you can't stop it anymore, the league is doing a great job, millions of kids playing soccer throughout the country, it is going to another level," he said.

"And the locomotive for all of this development is always the national team, in every country, so we want to do well. We want to inspire them and give them enthusiasm and belief."