Caitlyn Jenner at the Vanity Fair Oscar Party in Beverly Hills. Picture: Reuters

Reality TV star Caitlyn Jenner has revealed she hasn't spoken to Kim Kardashian West in nine months.

The former Olympian fell out with Kim over her tell-all book 'The Secrets of My Life', and Caitlyn has admitted the world-famous duo haven't spoken to each other since last year.

The 'Keeping Up with the Kardashians' star shared: "We haven't talked in nine months. I love Kim so much. It's such a huge loss in my life not having her there anymore. It's really sad.

READ: Kris Jenner - I fell 150 percent in love with Caitlyn

"I love all my children. I spent 25 years raising these kids."

Kim, 36, was angered by Caitlyn's decision to expose family secrets in her book.

But Caitlyn insisted she has no regrets about being so candid, saying she's proud of 'The Secrets of My Life'.

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Speaking on 'Good Morning Britain', Caitlyn said: "With that family, you'll notice on the show ['Keeping up with the Kardashians'] that I always kept my opinions to myself.

"I was living in a house with very opinionated women and I was always left in the background and kept my mouth shut."

Caitlyn - who was married to Kim's mother, Kris Jenner, from 1991 until 2015 - said the book represented her opportunity to offer her own take on the Kardashian family.

But she acknowledges it has damaged her relationship with Kim and Kris.

She shared: "This book was my story. I was finally giving my side of the story. It was completely honest and I continue to feel extraordinarily proud of my book.

"Unfortunately though, the Kardashians, particularly Kris, didn't react that way even though I went overboard to be nice and friendly."

Despite this, Caitlyn insisted she still loves Kim and admires how she's developed her business empire in recent years.

She said: "I love Kim so much, and have a lot of respect for her as a mother and business person."