Actor George Takei, who is best known for his role as Hikaru Sulu on Star Trek, has predicted nationwide gay marriage within the next 5 years.

The 76-year-old Takei became an outspoken supporter of LGBT rights after he publicly came out gay.

In 2008, he married husband Brad Altman in California shortly before voters approved Proposition 8, the state's constitutional amendment limiting marriage to heterosexual couples which was struck down last year.

Speaking to Forbes from SXSW, where he is promoting a documentary about his life, Takei said that marriage equality advocates have made “unimagined” progress.

(Related: George Takei, John Lithgow films to premiere at Sundance.)

“We have been making unimagined progress,” Takei said. “I mean just within the last decade. We now have 17 states plus Washington D.C. that has marriage equality. And I would venture to say, before five years is out we will have marriage equality throughout the land.” (The video is embedded on this page. Visit our video library for more videos.)