Khamenia is Duke's third notable commitment in the past two weeks, following the decisions of twin brothers Cameron and Cayden Boozer earlier this month.
"Duke was a place I visited and felt it was special from the moment I left campus. Coach [Jon] Scheyer believes in me and my abilities," Khamenia told ESPN. "Duke is a special place that has put out a lot of great players and ultimately helped them develop."
Khamenia built a strong relationship with Scheyer during his recruitment.
"Coach Scheyer is a young coach who played at Duke, so he understands both sides of being a player there and a coach," Khamenia said. "He connects with his players on a personal level and knows how to help them grow and improve."
A 6-foot-8 forward at Harvard-Westlake (Calif.), Khamenia turned heads at the recent USA Basketball junior national team minicamp, leading NBA scouts to tell ESPN's Jonathan Givony that they wouldn't rule out Khamenia being a one-and-done prospect.
He also represented USA Basketball at the FIBA U18 AmeriCup over the summer, starting all six games and helping lead the team to a gold medal. Khamenia averaged 7.7 points, 6.3 rebounds and 3.0 assists during the event.
Khamenia owns as much offensive skill and as high a basketball IQ as anyone in the class. His offensive versatility and shooting touch from a variety of ranges makes him hard to defend. He uses a jab step, shot fake and pass fake, and his ability to make shots on the move is strong. He operates effectively without the ball, cutting, screening and attacking the offensive glass.
"Nik is an incredible young man who has grown and developed every single year," Harvard-Westlake coach Dave Rebibo said. "He has a blue-collar approach to basketball while having a tremendous amount of skill, vision, IQ and toughness. He is the ultimate winner."
Duke is now the only program in the country with three top-35 commitments in the 2025 class.
"The Boozers are ultimately winners, and they are like-minded to me," Khamenia said of his fellow Duke recruits. "I have talked to them a bit and have played against them as well. I respect them a lot, both as players and as people."