Jurgen Klinsmann will put his personal friendship with Joachim Low to one side and tell his United States players to go out with aggression for "a battle" with Germany.

The two countries meet in Group G's finale in Recife on Thursday where a draw would send both teams through to the last 16.

FIFA has made it clear they will not tolerate any collusion between the teams and Klinsmann insisted the USA would be going all out for victory.

Low was Klinsmann's assistant when he was Germany coach in 2006 and the two men remain close friends but the USA coach insisted there will be no stitch-up of the result.

He said: "Every player wants to be involved in this and we will approach it with determination and in a focused way.

"We will come out and be very aggressive and give Germany a real battle.

"Joachim Low is a close friend of mine and I have a lot of admiration for what he has achieved over the last eight years but we will leave the text messages and phonecalls for a couple of days."

A FIFA spokeswoman said they "believe and trust" both teams will try their hardest - there was an infamous match between West Germany and Austria in 1982 that saw both teams qualify at the expense of Algeria.

The spokeswoman said: "We believe and trust and hope and rely that the teams will pay at their best. We believe this is a FIFA World Cup and they have the spirit of fair play."

The USA have five German-Americans in the squad including defender Fabian Johnson who plays his club football for Bundesliga club 1899 Hoffenheim, but he pointed out that the USA team had gone all out to beat Panama in qualifying despite the result allowing Mexico also to get through.

Johnson said: "I don't think that is our nature [not to try] - everyone wants to win this game, like we did against Panama which helped Mexico qualify."

Midfielder Kyle Beckerman added: "Both teams will go out and try to win - it's a World Cup and you want to get as many wins as possible."

Klinsmann believes that Germany are potential winners of the whole tournament.

He added: "They are one of the three or four big teams in the World Cup who can go all the way and win it, they have that potential.

"It is very confident, high-paced football which is a wonderful way to play and it's just fun to watch the Germany side."