USA coach Jurgen Klinsmann has insisted that his players are ready and confident ahead of their World Cup Group G opener against Ghana at Estadio das Dunas on Monday night.

The German said that Ghana are one of the strongest African nations in the tournament, but his side have been well prepared with their research into all their Group G opponents.

"We feel very confident going into this game against Ghana," Klinsmann told reporters. "But we also know what Ghana represents - one of the top nations in Africa, no doubt about it.

"I wanted to see them myself and get an impression, and we have that. We know about our strengths, and what we need to improve still, and we've been working on that for a month."

Klinsmann has been USA coach since 2011.