Gyasi Zardes bagged a brace and Christian Pulisic became the nation's youngest ever goalscorer as the United States fine-tuned their Copa America Centenario preparations with a dominant 4-0 win over Bolivia on Saturday.

In USA's final warm-up fixture before their Copa America curtain-raiser against Colombia on Friday, Zardes led the way as captain Michael Bradley pulled the strings in midfield in Kansas City.

Zardes opened the scoring at Children's Mercy Park approaching the half-hour mark before centre-back John Brooks doubled the lead 11 minutes later.

USA moved clear thanks to Zardes' effort seven minutes into the second half and 17-year-old midfielder Pulisic scored his first international goal in his third appearance to complete the rout as Jurgen Klinsmann's men made it three wins in a week heading into the centenary edition of the Copa, while condemning fellow participants Bolivia to a fourth consecutive defeat.

Klinsmann made five changes to the team that edged Ecuador 1-0 on Wednesday, with Geoff Cameron, Michael Orozco, Matt Besler, Alejandro Bedoya and Bobby Wood coming in for Fabian Johnson, DeAndre Yedlin, Steve Birnbaum, Graham Zusi and Kyle Beckerman.

Playing for the first time since March's World Cup qualifying defeat to Argentina, Bolivia - drawn alongside Chile, Argentina and Panama in Group D - rarely troubled USA, who took control of proceedings in the 26th minute.

Some neat interchange play between Orozco, Clint Dempsey and Bedoya resulted in Zardes poking the ball past onrushing Bolivia goalkeeper Guillermo Vizcarra.

It was not long before USA stamped their authority on the match as Brooks put the hosts 2-0 up with eight minutes remaining in the first half.

A quick free-kick from Bradley played in Bedoya, who squared the ball across the six-yard box for towering centre-back Brooks to side-foot home.

USA continued where they left off in the second half, with Zardes scoring his fifth international goal.

In the thick of the action again, a cross-field pass from Bradley found Wood, who chested it down and picked out Zardes  inside the six-yard area. 

USA keeper Brad Guzan finally had something to do past the hour-mark, on hand to deny substitute Rodrigo Ramallo.

And at the other end, Borussia Dortmund teenager Pulisic came off the bench to etch his name in history.

After dispossessing Bolivia, fellow substitute Darlington Nagbe - the last-gasp hero against Ecuador - burst through midfield and teed up Pulisic, who composed himself to find the back of the net.