Mauricio Pochettino conceded United States is enduring a "painful" spell after a 4-0 defeat to Switzerland in its final warm-up match before the Gold Cup.

The Stars and Stripes were well beaten by their European opponent in Nashville, meaning they have suffered four successive losses on home soil for the first time since June 1988.

Switzerland scored four times in the space of 36 minutes at Geodis Park; the quickest USA has ever conceded four goals in a single game.

Dan Ndoye broke the deadlock while Michel Aebischer tapped in a second goal in the 23rd minute. Breel Embolo and Johan Manzambi then struck twice in the space of three minutes to complete the rout.

"I don't like to put excuses. I know I am guilty, I am responsible," Pochettino said. "If people want to criticize, then criticize me; that's no problem. 

"It was my decision, and the decision didn't work. It's painful because you don't want to improve losing games."

USA is on a four-match losing streak ahead of its Gold Cup opener against Trinidad and Tobago on Monday.

Signs are not overly promising for the Stars and Stripes, who are also set to co-host next year's World Cup, but Pochettino is confident the team will have the support of its home crowd.

"The fans are going to be there, for sure, in the Gold Cup and the World Cup," he said. "I have no worries about that. The fans are going to be with the team."

"You have to take your licks and understand where things went wrong, and try to put them right in the next five days," added defender Tim Ream. "There are some individual errors that we make, and we get punished for them at this level."

USA failed to register a single shot on target for the first time on American soil since doing so against Argentina in the 2016 Copa America semi-final.

Although it was a much-changed side, without notable senior players, including Christian Pulisic, Yunus Musah, Weston McKennie, Timothy Weah, Giovanni Reyna, Antonee Robinson, Tyler Adams, Folarin Balogun and Sergino Dest.

Defender Walter Zimmerman insists there is no need to panic, highlighting an example of how fortunes can quickly change.

"I know in this sport, you're not judged on one game, one half, but you've got to be able to bounce back mentally, physically, emotionally," he said.

"We've played hundreds of games in our career. Some are going to be amazing. Some aren't going to be so good.

"It's really easy to look at one game, one half and be like: 'Oh, this is all going to pieces; they can't come back from this'. 

"But you even look [to] the build-up to the 2022 [World Cup], we take down Morocco 3-0, and they make it into the semi-final. Things change; that was six months apart. It's not the end of the world."