While speaking with PEOPLE afterher death at age 99on Friday, Witjas opened up about the late star and their years-long relationship, as well as how White appreciated the kindness she received from the world over.

“She knew it, but I would tell her often,” Witjas says. “Even when she wasn’t working, I said, ‘Betty, millions of people out there are still asking for you. You’re getting your fan letters, I’m getting offers for you.’ "

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Betty White and Jeff Witjas.Vivien Killilea/Getty

Betty White and talent agent Jeff Witjas attend The TMA 2015 Heller Awards on May 28, 2015 in Century City, California.

“Betty lived a great life and she lived a life that she chose. She was happy,” Witjas adds. “Every time I told her, ‘Betty, you’re loved,’ she would look at me with a wry smile and say, ‘Really?’ I hope she knew. I think she did. It was something beyond love.”

Witjas — who previously confirmed to PEOPLE that the actress"died peacefully in her sleep”— had a close bond with theGolden Girlsstar, who he considered to be not only a work colleague, but a dear friend.

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Betty White.getty

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“She was an incredible lady. Hard to put into words,” he tells PEOPLE. “We had a special relationship, far more than just a client.”

“We became really good friends and we always laughed no matter what we did. She was always positive and she always saw the bright side,” Witjas continues. “She promised me she would live to 100 — and she almost did.”

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Continuing to speak about White, Witjas says that the iconic star spent most of the final years of her life in her L.A. home.

“[She] was really simply spending each day at her home. She didn’t go out. She was under a doctor’s care, not for any reason, other than just being careful with COVID,” he says.

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“I know there was a period where she would address all the fan letters,” but that eventually slowed down. “I think, she just didn’t have the energy to respond the way she used to,” Witjas adds. “She was reading, she just lived her life. She was home in her comfortable surroundings.”

Witjas says that he and White also chatted about herupcoming 100th birthday.

“We kidded. I said, ‘Betty, we know you’re going to turn 100. Let’s start focusing on 101.’ I mean, that’s really how we kidded around,” he shares. “She never made it a big deal.”

“Wow, that’s a pretty large number,” she once told him. “But we didn’t sit there and say, ‘Betty, how did you do it? What did you do?'” Witjas explains, adding that she often joked about her diet.

Witjas also noted that White was well aware of her advanced years and chose not to replace her beloved golden retriever Pontiac after he died a few years ago.

“I had asked her if she wanted another animal, and she said to me she would prefer not because if she got a puppy or she went to a shelter, she’d always figured that the dog would outlive her,” he says. “And I would kid her. I said, ‘Betty, you’re outliving everybody. You’re not going anywhere.’ But she was so sensitive to animals.”

“Her work speaks for itself,” Witjas adds, joining millions who now mourn White. “Her legacy was sealed. It was sealed years ago.”

source: people.com