Ashton Kutcher will ''never stop loving'' Demi Moore's children.

The 41-year-old actor - who is married to Mila Kunis and has daughter Wyatt, five, and son Dimitri with her - was previously married to Demi for eight years between 2005 and 2013, and during that time he helped raise her three children from her prior romance with Bruce Willis - Rumer, 31, Scout, 28, and Tallulah, 26.

And although Ashton admits he doesn't ''hang out'' with Demi any more, he insisted he makes a ''conscious effort to stay in touch'' with her three daughters, because he'll never forget the bond they shared when he was their step-father.

He said: ''It was eight years. Tallulah was eight or nine, she was the youngest. Rumer was 12 or 13 when we first started dating. When we were getting divorced, Tallulah was graduating high school.

''I was helping raise teenage girls through their adolescence. I love them. I'm never going to stop loving them and respecting them and honouring them and rooting for them to be successful in whatever they are pursuing.''

But the 'Ranch' star said he doesn't force the trio to stay in contact with him, because he knows he's not their father.

During an appearance on Marc Maron's 'WTF' podcast, he added: ''I think you try ... but at the same time I am not their father. I was never trying to be their father. I always had respect and honoured Bruce [Willis], and I think he's a brilliant human being and a wonderful man. If they don't want an engagement with me, I'm not going to force it upon them. But they all do and it's great.''

Meanwhile, Rumer recently spoke about her relationship with Ashton, as she said she was ''so angry'' at the 'That 70s Show' star for ''taking away'' her mother.

She said: So much of that time, especially with Ashton, I was so angry because I felt like something that was mine, had been taken away.

''When she wanted to have another baby, it was like, and then it wasn't happening, and then there was so much focus on that, it was like, 'Oh, well we're not enough.' ''