LOS ANGELES (AP) — Actor Walter Koenig, who played Ensign Pavel Chekov, the youthful Russian navigator on the “ Star Trek ” television series and several movies, has died. He was 90.

Koenig died Monday at his home in the North Hollywood neighborhood of Los Angeles, talent agent Zachery McGinnis said in a statement.

In “Star Trek,” Ensign Chekov was the sole Communist-bloc member of the spaceship Enterprise bridge staff. His friendly, supportive presence showed how the rival nations (in the far-off future in which the show was set) were capable of working together.

Speaking Russian-accented English, Chekov embodied stereotypical Russian personality traits, including fierce pride, love of poetry and blind loyalty.

“Star Trek” ran on NBC from 1966 to 1969 and has had an almost unprecedented afterlife as fans, or Trekkies, kept interest in the show alive.

Koenig was born Sept. 14, 1936, in Chicago, the son of a businessman. He graduated from the University of California, Los Angeles in 1958, then studied acting at New York's The Neighborhood Playhouse for two years. He began getting television roles in the early 1960s, appearing on “Mr. Novak” and “Ben Casey.”

“My heart is heavy,” Koenig's castmate, George Takei, said in a post on the social platform X. “Walter was more than Chekov. He was a writer, a teacher, a thoughtful man, and a loyal friend.”

Koenig was the best man at Takei’s 2008 wedding to Brad Altman, his partner of more than two decades.

“Walter’s legacy extends far beyond the screen. Through countless convention appearances and interactions with fans, he shared his kindness, wit, and appreciation with everyone fortunate enough to meet him. He understood what Star Trek meant to people and embraced the community that grew around it,” McGinnis said. “Thank you, Walter, for the memories, the inspiration, and for boldly going where few have gone before.”

McGinnis said Koenig died surrounded by his daughter and niece.

Koenig played Chekov in seven “Star Trek” movies starting in 1979, as well as innumerable other spinoffs, including writing a “Star Trek” book, “Chekov's Enterprise,” in 1980. The TV show has also inspired two spinoff TV series with new casts, and conventions that draw thousands of fans.

After “Star Trek” ended, Koenig continued acting and wrote scripts for “Family,” “The Incredible Hulk” and other shows. He also taught part time at UCLA and other schools.

Koenig also worked in the burgeoning field of computer games, including some with a “Star Trek” theme. In 1995, he took a role in the CD-ROM game “Maximum Surge.”

“I'm at a point where I could opt in my life for complacency and a bit of predictability, or I could have one last holler — one last try for adventure,” Koenig told The Associated Press in 1995. “I'm of the opinion that adventure is still a very enticing and exciting option.”

He returned to the science fiction genre with occasional appearances in the syndicated 1990s TV series “Babylon 5.”