Kwesi Appiah says a lack of concentration was to partly blame for Ghana's opening World Cup Group D defeat to the United States.

Ghana suffered a 2-1 loss in their third meeting against the U.S.

Clint Dempsey sent the U.S into the lead in the first minute of Monday night's game at the Estadio das Dunas in Natal as he dribbled way into the box to side-foot home but Andre Ayew equalised with seven minutes remaining after latching onto a beautiful back-heel pass from captain Asamoah Gyan.

However, substitute John Brook’s header five minutes to end the game secured a first victory for the Americans over the Black Stars.

"I think that early goal was a disaster, it was unfortunate," Appiah said after the match.

"Loss of concentration cost us big time.

"All I can say is that it was a very tough game and when you play at this high level any little mistake can cost you dearly."

Ghana could not translate their domination and attacking play into goals though they created lots of chances.

"We had a lot of the ball and created a lot of chances, but we didn’t make the most of our chances, but USA took theirs."

As he now goes back to reorganize his side to face group leaders, Germany who thrashed Portugal 4-0, Appiah expects the Black Stars to be ready for the crucial game in Fortaleza on Saturday.

"It’s not going to be easy to qualify from the group, but we’ll give everything to do just that," he said.

"We’re going to have to play well against Germany and I know we’ll give them a good game."