Kim Kardashian West is not mincing words when it comes to Caitlyn Jenner‘s revealing new book.

During an appearance on The Ellen DeGeneres Show that will air Thursday, the 36-year-old reality star spoke honestly about Jenner’s new memoir, The Secrets of My Life, claiming that parts of the revealing book aren’t true.

“My heart breaks for my mom [Kris Jenner,] you know, because I feel like she’s been through so much and [Jenner is] promoting this book and she’s saying all these things,” Kardashian West told host Ellen DeGeneres. “I don’t think it’s necessary and I just feel like it’s unfair, things aren’t truthful.”

In the new memoir that was released earlier this week, 67-year-old Jenner opened up about everything from her decision to transition in 2015 to her decades-long marriage to Kris. The Kardashian-Jenner family matriarch, 61, has reacted angrily to the passages about the claims that she knew Jenner was transgender before they got married.

“Kendall and Kylie [Jenner], that’s their dad and I think my mom’s been so respectful for so long and always wanting Caitlyn around and always wanting to have a great relationship with Caitlyn,” Kardashian West told DeGeneres.

“I feel like it’s taken [Jenner] a really long time to be honest with herself, so I don’t expect her to be honest about my mom now. But it’s just so hurtful. I wish her all the success in the world, but not at our expense.”

Kardashian West’s relationship with Jenner has seen its up and downs in the wake of the Olympian’s transition. The mom of two has been a vocal supporter of Jenner, but has urged the star to not “bash” the Kardashian family.

Now, Kardashian West revealed she hasn’t spoken to Jenner in weeks, but added, “I’ll always love her.”

WATCH: Kim Kardashian West On Her Strained Relationship With Caitlyn Jenner: ‘I Haven’t Talked To Her In A Couple Weeks’

“That was my stepdad for so many years. She taught me about character and so much growing up and I just feel like I don’t respect the character that she’s showing now,” the Keeping Up with the Kardashians star told DeGeneres.

“Like I said, I’ll still always have major love for her, for who she was in my life … It’s still Kendall and Kylie’s dad so I wanna be respectful, but I just feel like there’s no need for a book.”

She added: “Tell your story, but don’t bash other people. I just think it’s not, like, tasteful.”