Trailblazing television star Betty White gave a revealing interview about turning 100 and her secrets to a long life just weeks before she died. 

White's agent and close friend, Jeff Witjas, confirmed on Friday morning local time that the 99-year-old had died, ahead of her milestone birthday on January 17. 

"I will miss her terribly and so will the animal world that she loved so much," he told PEOPLE in a statement. 

"I don't think Betty ever feared passing because she always wanted to be with her most beloved husband Allen Ludden. She believed she would be with him again." 

The near-centenarian and star of The Mary Tyler Moore Show and The Golden Girls was a TV fixture for decades and became a cultural icon in her 80s and 90s. 

n this May 18, 1976 file photo, cast members of the "Mary Tyler Moore Show" pose with their Emmys. Ed Asner(left), Betty White, Mary Tyler Moore and Ted Knight. Photo / AP 

Speaking to People in an interview published on December 28, White said she felt "so lucky to be in such good health and feel so good at this age". 

"It's amazing," the veteran actor added. 

White said she was "born a cockeyed optimist", describing it as the key to her upbeat nature and happy life. 

"I got it from my mum, and that never changed," she said. "I always find the positive." 

White echoed a similar sentiment in the lead-up to her 95th birthday in 2018, telling Parade the key to happiness was simply to "enjoy life". 

"Accentuate the positive, not the negative. It sounds so trite, but a lot of people will pick out something to complain about, rather than say, 'Hey, that was great!'" she said. 

"It's not hard to find great stuff if you look." 

As for the secrets to her good health, White joked to People: "I try to avoid anything green. I think it's working." 

White's former castmates – including Sandra Bullock, Ryan Reynolds, and Mary Steenburgen – also opened up to People about working with the legend. 

Actress Betty White poses for a portrait following her appearance on the television talk show "In the House" in 2009. Photo / AP 

"Timing isn't easy in comedy, because you have to navigate other people's timing. Betty pivots like I have never seen, making it look seamless. The rest of us just remain silent and pray we're not cut out of the scene," Bullock, who starred in The Proposal alongside White, said. 

She added that she hoped White's 100th birthday would be spent "the same way she has celebrated every day of her life, with humour, kindness and a vodka on ice, toasting to the fact that she's a badass who has left us all in the dust". 

"Betty lives a life of happiness. She always thinks of others first, and she stays positive no matter what," Witjas told People. 

Reynolds, who said he'd been a fan of White's "for as long as I can remember", said, "I heard that scripts for Golden Girls were only 35 pages, which makes sense because so many of the laughs come from Betty simply looking at her castmates." 

Reacting to the news of her death on Twitter, Reynolds paid tribute to the star. 

"The world looks different now. She was great at defying expectation. She managed to grow very old and somehow, not old enough. We'll miss you, Betty. Now you know the secret," he wrote. 

White, possibly best known for her character on The Mary Tyler Moore Show and, of course, her portrayal of Rose Nylund on The Golden Girls became a sought-after personality on talk and game shows in her twilight years. 

Actors from the television series "The " Golden Girls" stand together during a break in taping in 1985 in Hollywood. Estelle Getty (left), Rue McClanahan, Bea Arthur and Betty White. Photo / AP 

"Betty White for the past 30 years turned herself into a piece of performance art," Syracuse University TV professor Robert Thompson told the New York Post. 

"If Betty White was scheduled you knew you were in for some fun. The older she got, the more television tolerated more candid discussion, she really became known [for] you never know what's going to come out of her mouth." 

In 2010, she became the oldest person to ever host Saturday Night Live, aged 88, with the performance winning her a seventh Emmy. 

- by Natalie Brown, news.com.au