NEW YORK — "Believe."

That word has over the last few years become closely associated with America's most famous soccer coach, the fictional Ted Lasso of the Apple TV series of the same name. The same mantra is now the message coming from the most celebrated and accomplished coach in U.S. men's national team history.

[RELATED: How Mauricio Pochettino will immediately impact the USMNT]

Mauricio Pochettino was officially unveiled as the USMNT's new boss at a grand press conference in midtown Manhattan on Friday, and when the former Chelsea, Paris Saint-Germain and Tottenham Hotspur manager was asked what he wants to accomplish with the Americans as the country prepares to co-host the biggest sporting event the world has ever seen 21 months from now, Pochettino didn't attempt to manage what even the most optimistic U.S. fans might see as a wholly unrealistic expectations.

"We have time, and we need to really believe in things, in big things," the 52-year-old Argentine said. "We need to believe that we can win all the games, that we can win the World Cup."

There's obviously a huge difference between thinking you can win the game's most coveted trophy and actually doing it — something Pochettino no doubt understands as well as anyone. But he also knows that to have any sort of success in 2026, his first order of business has to be restoring the USMNT's badly shaken confidence.

After becoming the first Copa América host to be knocked out in group play earlier this summer, the squad's self-assurance is at its lowest point since the program's epic failure to qualify for the 2018 World Cup. So Pochettino's immediate goal must be to get his players to once again play without fear, to believe that they can stand toe-to-toe with any opponent — no matter which one.

"Of course the confidence was a little bit low after the Copa América," Pochettino said. "I think it's a very good generation of players. We need to show that we play like a collective on the pitch."

That work will begin in earnest next month. Pochettino's first match in charge of the U.S. will come on Oct. 12 in Austin, Texas, where the Americans will meet Concacaf rival Panama in a so-called friendly. 

"For me," Pochettino said, "it's not friendly."

Getting to not just know the players but to see them in camp, on the training field, in the meal room at the hotel, will let him and his three-man staff of longtime assistants Jesus Perez, Miguel D'Agostino and Toni Jimenez know exactly where things stand. "We have a plan, and the most important thing is to feel how they are on the field together," Pochettino said. "[The players] can express themselves, how they see the team."

Pochettino said the idea is to eventually base himself in the U.S. full-time. But house-hunting in the Atlanta area — where U.S. Soccer is constructing a state-of-the-art training facility — won't begin immediately. He'll remain in his adopted hometown of Barcelona for now, enabling him to keep close tabs on the USMNT's mostly European-based player pool. Building those relationships will be crucial.

"They need to feel our support clearly, to feel that we care for them," he said. "When the players feel that you care, you get the best [out of that] player."

As the team's dismal Copa performance showed, there is a lot of work to do. "Improvement for us is really important," he said. "We want to play nice football, good football, exciting football, attacking football."

"They need to know exactly what we need to do, how we need to compete, how we need to behave like a team," Pochettino added. "And the potential is there, the talent is there."

It's part of what attracted one of Planet Fútbol's most coveted club coaches to his first international job. It wasn't the only thing, though. Pochettino has long been intrigued by the U.S. as a country as much as a soccer nation.

"It's a winning culture, a winning mentality," he said. With a home World Cup on the horizon, the opportunity was too good to pass up. For the U.S. Soccer Federation, the hiring is nothing short of a coup. 

"His football résumé speaks for itself," said U.S. president Cindy Parlow Cone. "Beyond that, also his passion — and you've heard it from him today — and his belief that we can go and do great things and that he can help us get there. Put all that together, and we believe that we have the best person in the world for this job." 

"It's about creating something special — that's the most important thing," Pochettino said.  

Against the truly elite soccer nations — just eight have ever hoisted the World Cup — that won't be easy. It will be next to impossible against any opponent if the mentality isn't hard as nails. 

"We are going to compete," promised Pochettino, who arrives with a reputation for getting the most out of his players and also developing talent from within.

That's the starting point, of course. Where the U.S. goes from there is up to them. There are no limitations as far as Pochettino is concerned. "If you said to me that I need to pick only one word," he said when asked what convinced him and his staff to leave European club soccer behind and take the leap the U.S. job represents. "Because we believe. We believe we can work together to try to achieve what people, and us, all want: to win, and not only win games but to go for big trophies and to be there, competing, for the World Cup."

"We are here," he said, "because we want to win."

Doug McIntyre is a soccer reporter for FOX Sports. A former staff writer with ESPN and Yahoo Sports, he has covered U.S. men's and women's national teams at FIFA World Cups on five continents. Follow him @ByDougMcIntyre.