Booker's commitment comes as the Suns are preparing for their first Western Conference finals since 2010 and will leave the 24-year-old with limited recovery time before Team USA begins play in Tokyo on July 25 against France.
He is the second player to reportedly join Team USA on Friday, along with Washington Wizards guard Bradley Beal, who will also be making his first Olympic appearance after leading the Americans in scoring on their way to an undefeated run at the under-17 world championship in 2010.
Beal, whose commitment was first reported by The Athletic, was a candidate for the team that won gold at the Rio de Janeiro Games in 2016 and again for the team that finished seventh at the Basketball World Cup in China two years ago. Beal wound up withdrawing from consideration in 2016 because of injury concerns and in 2019 for family reasons.
A three-time All-Star who was announced earlier this week as an All-NBA selection for the first time, Beal averaged a career-best 31.3 points per game for Washington this season.
Booker and Beal join a backcourt that will include Portland Trail Blazers guard Damian Lillard, who said Thursday that he has several reasons for wanting to play -- the chance to be coached by Gregg Popovich among them. The U.S. is also expecting forwards Draymond Green, a 2016 Olympic gold medalist, and Jayson Tatum to be part of the Tokyo-bound roster.
USA Basketball has been aiming toward filling the 12-man roster for the Olympics by the end of this month. The Americans -- bidding for a fourth consecutive Olympic gold medal -- will convene for training camp in Las Vegas on July 6.
The Associated Press contributed to this report.