Relief and utter joy washed over American fans on Tuesday as the United States beat Iran 1-0 in a nailbiter to reach the last 16 of the World Cup, after they shockingly failed to reach the 2018 tournament.

The United States are four years away from co-hosting the quadrennial with Canada and Mexico, and watching "Captain America" Christian Pulisic bundle the ball home on Tuesday, fans said their team showed they belong on soccer's biggest stage.

"This (victory) means we have an official international presence," said 34-year-old real estate investor Mark Allison, who watched the match on a giant outdoor television at Park 101 bar and restaurant in Carlsbad, California.

"The next 10 years for U.S. soccer has a bright future. I've never seen so many USA fans for soccer ever until now. The U.S. coming together and uniting as a country, despite all the chaos in the world is a beautiful thing."

U.S. President Joe Biden, who had just wrapped up remarks at an economic event in Michigan and was speaking to people in the audience, got back on the microphone on stage as soon as the game ended.

"USA, USA, that's a big game, man," he said. "When I spoke to the coach and the players, I said, 'You can do this.' They went 'eh.' They did it, God love 'em. Anyway, just thought you might want to hear."

The United States next face the Netherlands on Saturday.

Watching the game at Fire Pitch in Chicago, Faith Enenbach, 30, said Tuesday's win was a satisfying reward for eight years of waiting to see her country back in the World Cup.

"People are hungry for this," she said. "We didn't make the World Cup the last time and now to be advancing forward is just huge."