Actor Keanu Reeves is looking forward to returning to the weird world of "The Matrix" after checking out the latest sequel's "ambitious" script.

The movie star was on the red carpet for the premiere of his producer sister Karina Miller's film, "Semper Fi", in West Hollywood on September 24, when he was asked about "The Matrix 4".

"It's very ambitious - as it should be," Reeves told etonline.com.

Miller then stepped in to remind the media it was her big night and Reeves was just a guest.

"He's always been so supportive and so protective of me doing my own thing and that I will always really appreciate," Miller said.

The "Semper Fi" cast, including Leighton Meester and Jai Courtney, joined the siblings at the premiere for the film, which proud brother Reeves called "a great accomplishment", adding, "It's a wonderful film."

Reeves and Carrie-Anne Moss are reprising their roles as Neo and Trinity in "The Matrix 4", while Lana Wachowksi, who directed the first three movies with sister Lilly, is directing again.

The movie is expected to begin filming in early 2020.