USA national team coach Bob Bradley admits his side has grown stronger in the past few years and admits tough experiences along the way prepared them for Wednesday night's last-gasp victory over Algeria.

The Americans needed 91 minutes to overcome the plucky African nation but managed to get the goal they required to progress to the World Cup Round of 16.

Bradley said the fact the team had grown stronger together and came through some adversity on the journey had held them in good stead.

"It's a lot of things. In this last cycle, guys have grown, taken leadership roles, as a team we've grown stronger, we've had experiences where we've been hardened," he said.

"Landon (Donovan) said the expression 'the part you can control.' We believe that in soccer sometimes you can't always control a call or a bounce, but you can control what you're all about as a team, what you put into it, how committed you are to giving everything in the game. I think that has become the special quality of this group."

Bradley touched on last year's Confederations Cup in South Africa as the perfect foundation to build on for a tournament such as the World Cup.

"The experience at the Confederations Cup was important for us. We played very good teams and we had to fight through the group, ultimately we had a great victory against a team like Spain," he added.

"But at the end of the day, we remember that we had a 2-0 lead at halftime against Brazil and we didn't come away as champions. So there's a disappointment, but that disappointment comes also with the belief and the hope that we're coming back in a year and we're going to try and take it a bit further. It's those experiences that help us grow."