In her first interview to promote her new book, Huma Abedin said she did not think an unnamed senator sexually assaulted her when he kissed her at his apartment, some time in the mid-2000s.

She also said she would “take to her grave” her part in the emails investigation which cost Hillary Clinton dearly in the 2016 presidential election, which the candidate lost to Donald Trump, though she knew it was not all her fault.

Abedin describes the incident with the senator in Both/And: A Life in Many Worlds, which will be published on Tuesday. The Guardian obtained a copy and reported Abedin’s description of the kiss.

After making coffee, Abedin writes, the senator sat next to her on the couch, “put his left arm around my shoulder, and kissed me, pushing his tongue into my mouth, pressing me back on the sofa.

“I was so utterly shocked, I pushed him away. All I wanted was for the last 10 seconds to be erased.”

Abedin does not give clues to the senator’s identity.

She also writes that memories of the kiss came back in 2018, during Brett Kavanaugh’s supreme court confirmation hearings, when the judge was accused of sexual assault. In Abedin’s description, Kavanaugh’s accuser, Christine Blasey Ford, was accused of “conveniently remembering” details. Kavanaugh denied the accusations and was confirmed to the court.

The pressure group Rainn (the Rape, Abuse & Incest National Network) defines sexual assault as “sexual contact or behavior that occurs without explicit consent of the victim”.

Speaking to CBS Sunday Morning, Abedin said: “I did go back to a senator’s apartment, a senator who I knew and I was very comfortable with, and he kissed me in a very shocking way because it was somebody who I’d known and frankly trusted.”

Her interviewer, Norah O’Donnell, asked: “Are you suggesting that senator assaulted you?”

Abedin paused, and said: “I’m suggesting that I was in an uncomfortable situation with … I was in an uncomfortable situation with a senator and I didn’t know how to deal with it and I buried the whole experience.

“But in my my own personal opinion, no, did I feel like he was assaulting me in that moment? I didn’t, it didn’t feel that way. It felt like I needed to extricate myself from the situation. And he also spent a lot of time apologising and making sure I was OK and we were actually able to rebalance our relationship.”

Earlier this week, Business Insider reported that senators from both parties expressed concern that the unnamed senator may have assaulted others.

On CBS, Abedin was also asked what she thought Clinton most valued about her.

“I think she would say her loyalty,” she said. “And I would say the same about her. I have tested that. Not intentionally, but I have tested it … I’ve made her life difficult with things that have happened in my personal life.”

Abedin is estranged from her husband, the former congressman and New York mayoral candidate Anthony Weiner, who served time in prison for sending explicit text messages to a teenage girl.

A laptop belonging to Weiner and Abedin became part of Clinton’s 2016 presidential election defeat, when the FBI seized it as part of investigations into Clinton’s use of private email while secretary of state.

“I think I’m going to take it to my grave,” Abedin told CBS. “It took me a while to reconcile that it was not all my fault.”

She added: “I have reconciled – and it took me a while to reconcile – that it was not all my fault. I lived with that. I did. I don’t believe that anymore.

“It’s more a sense of an ache in the heart, that it didn’t have to be. And also, my belief that [Clinton] would have been an extraordinary president, that she really would have, and what it meant for women and girls, not just in this country but around the world.”

Asked why she wrote her book, Abedin said: “I think for most of my adult life, certainly in the last 25 years that I’ve been in public service or in the public eye, I have been the invisible person behind the primary people in my life. But what I realise is that if you don’t tell your story, somebody else is writing your history.”

She also discussed Weiner and how she discovered his various infidelities. She and her husband, she said, were “just two severely broken, traumatised people”.

Asked how their relationship was now, she said: “We’re good. He is my co-parent. And I learned the full truth, I processed it and moved on. I wish him well. He, I hope, wishes me well. I think he does.”

Asked if she was still angry with Weiner, Abedin said: “I can’t live in that space anymore. I tried that. It almost killed me.”