NEW YORK, (Reuters) – As a former World Cup winner,  Juergen Klinsmann knows what it takes to rule the world.

The United States has similar ambitions but have not come  close to reaching their goals so have hired Klinsmann to teach  them how.

In many ways, it looks like a perfect match. Klinsmann has  the international experience and know-how, and the Americans  have the money and the will to succeed.

But the German, who said he has developed an understanding  of the American mind-set after spending the last 13 years in  California and is married to an American, is also a realist.

“I can’t promise anything,” the former striker told  reporters at a news conference yesterday. “There are a lot of  difficult challenges ahead.”

With dozens of journalists, photographers and television  crews crammed into the lobby of a Manhattan store, he was given  the sort of reception normally reserved for a National Football  League star quarterback changing teams, but there was no  chest-beating or trash-talking, just a dose of reality about  the challenges U.S. soccer faces.

“I believe that soccer has to reflect the culture of the  country,” Klinsmann said.

“I’ve studied the U.S. the last 13 years, and it’s going to  be quite a challenge. There are a lot of opinions, a lot of  ideas from youth soccer to college, which is a model different  from anywhere in the world.”

Later, he said that winning the World Cup was not a  realistic short-term goal for the U.S. side, despite the team’s  improved performance in recent years.

“It will take a tremendous amount of hours for the kids to  play the game in order to one day break into the top four in  the world and maybe contend, compete really, for the World Cup  title,” he told Reuters.

“It is really down to what comes through the youth ranks  over the next years in order to see if you can ever compete for  a World Cup final.

“I think we’re still quite a long way away from that, but  it should be your goal. It should be your goal to be where the  girls (national women’s team) were a couple weeks ago in  Frankfurt (Women’s World Cup Final), but it all starts on the  grassroots level.”

Sunil Gulati, president of the U.S. Soccer Federation,  described Klinsmann’s appointment as the start of a new era for  the sport in America but made no wild predictions either.

“We’re heading in the right direction and we’re excited to  have Juergen Klinsmann leading our team and technical program,”  said Gulati, who announced last week that Bob Bradley had been  fired as national coach.