Chelsea-bound Borussia Dortmund midfielder Pulisic, Schalke's McKennie and RB Leipzig's Adams were all missing during Berhalter's first training camp in January, which only included US-based players.

However the trio headline a 24-man squad for the games against Ecuador on March 21 in Orlando and South American champions Chile in Houston on March 26.

The squad also sees a return for veteran midfielder Michael Bradley and Newcastle's DeAndre Yedlin.

Fulham defender Tim Ream has earned is first call-up to the squad since 2017, along with Omar Gonzalez, who plays for Mexican side Atlas.

"We thought it was important to tie some of the themes of last camp into this next camp and to have some consistency in the personnel made a lot of sense," said Berhalter.

"We still think we're able to evaluate a new group of players, and we think that is going to be valuable as we move into the Gold Cup," he added.

"We have other players that we have evaluated thoroughly in the January camp and we're going to bring back in the future, but not in this camp."

Speaking about the return of the veterans -- Bradley, Gonzalez and Ream are all into their 30s -- Berhalter added: "We have been saying all along that we thought it was important to have a veteran presence in the national team."

"It's important when you talk about the history, the heritage and culture of what it means to play for the national team."

This month's friendlies come just three months ahead of the 2019 Gold Cup, the regional championship for North America, Central America and the Caribbean, which takes place from June 15 to July 7.

United States squad

Goalkeepers: Ethan Horvath (Club Brugge/BEL), Sean Johnson (New York City FC), Zack Steffen (Columbus Crew SC)
Defenders: John Brooks (Wolfsburg/GER), Omar Gonzalez (Atlas/MEX), Nick Lima (San Jose Earthquakes), Aaron Long (New York Red Bulls), Daniel Lovitz (Montreal Impact), Matt Miazga (Reading/ENG), Tim Ream (Fulham/ENG), DeAndre Yedlin (Newcastle United/ENG)
Midfielders: Tyler Adams (RB Leipzig/GER), Michael Bradley (Toronto FC), Sebastian Lletget (LA Galaxy), Weston McKennie (Schalke 04/GER), Christian Pulisic (Borussia Dortmund/GER), Cristian Roldan (Seattle Sounders FC), Wil Trapp (Columbus Crew SC)
Forwards: Paul Arriola (D.C. United), Corey Baird (Real Salt Lake), Jonathan Lewis (New York City FC), Jordan Morris (Seattle Sounders FC), Christian Ramirez (LAFC), Gyasi Zardes (Columbus Crew SC)