United States captain Tyler Adams paid tribute to his team's unity during Tuesday's crucial 1-0 World Cup win over Iran, while defender Tim Ream applauded the skipper's impact.

Christian Pulisic got the winning goal for the USA just before half-time at Al Thumama Stadium, a victory that secured their progression to the last 16.

The build-up to the game was dominated by geopolitical topics due to the two nations' strained relationship, with this their first World Cup meeting since a clash at France 1998 that was dubbed the "most politically charged game" in tournament history.

Iran won that encounter 2-1 in Lyon, but this time the USA got the victory over the line. As superior as they were in the first half, Gregg Berhalter's men were far less dominant after Pulisic's forced withdrawal – due to a pelvic contusion that will be managed "day-to-day" – at half-time.

Iran piled the pressure on towards the end and went close twice in stoppage time, but the USA held out to set up a clash with the Netherlands.

Given they did not even qualify for the last World Cup, their progression shows how far the USA have come in recent years, and Adams' comments reflected the feel-good factor surrounding the team.

"For me, I have obviously dreamed of playing in a World Cup, and I didn't know when that time would come," he told reporters. "Obviously that has come now. I am very proud to be representing the US and this team.

"The group we have in this locker room is superb, every day we show up and try and get better, and focus on getting better.

"Tonight was one of those nights where you knew you could look to your left and look to your right and there was someone battling for you."

The USA have only ever been beyond the last 16 at a men's World Cup once in its current format, back in 2002 when a Landon Donovan-inspired side reached the quarter-finals.

Standing in the way of matching that accomplishment are the Netherlands, and the size of the task facing the USA is not lost on Adams, who rates the Oranje among the best in Qatar.

"Obviously it is a big opportunity for us; an amazing game," he said. "We have obviously played against good teams here already like England; the Netherlands could be another favorite to win the World Cup and they have done really well to navigate their way through the tournament so far.

"They've some amazing players, we are going to have to be ready. For now, we will try to have some downtime and relax to regain our focus. Our coaches will obviously come up with a game plan to get us ready."

Adams' performance was vital to the USA prevailing, with the Leeds United midfielder's poise key to their first-half control and his tenacity important in disrupting an improved Iran after the break.

His 84 touches, 62 completed passes, and 12 recoveries were all highs for the match, while Adams also tallied the second-most tackle attempts (three) on the USA team, successfully taking back possession on each occasion.

Ream, playing behind Adams at center-back, saw his captain's performance at close quarters and was grateful for his protection.

"[Adams] makes everyone's job a little bit easier. The amount of ground he covers, his energy, tenacity, work rate; it's just incredible what he does on a football pitch.

"As he grows the team grows, you could see that. It's a pleasure to play behind him."

Of course, it was not the first time this week Adams has been under the spotlight.

Suffice to say, Ream joined the chorus of praise for how Adams handled that particular situation.

"I thought it was brilliant," Ream said. "It is what it is, that's the world we're living in right now.

"For him to handle it with the poise that he did, and the sincerity that he showed, I think was fantastic."