Actor Viggo Mortensen has opened up about his mother's battle with dementia, admitting he misses the conversations they used to share.

The Lord of the Rings star was raised by his American mum Grace after she split from his Danish father when Mortensen was aged 11, and he reveals they are still close and speak often.

While Mortensen reveals Grace seems "happy" despite being diagnosed with dementia, he misses the conversations he had with her.

He tells the Telegraph Men's Style magazine, "She knows who I am, but she get things mixed up. She always loved movies, and she probably instilled that interest in me. There are a couple of channels that show old-time movies, and she watches those a lot. But now she thinks that's what's really happening, and she thinks I'm in every single one. Which leads to some very funny conversations: 'I watched your movie. I can't remember what it's called, but Ingrid (Bergman) was very good, as she always is. You - not so much.' Then I'll ask her questions about it, and it was (1946 movie) Notorious, or something. Or she'll say, 'It's a nice day here, but the house next door exploded.' And I know that's something she just saw on the Tv.

"She seems happy, and she laughs a lot. But I do miss the conversations we used to have."