Mariah Carey had no idea she'd be able to build an empire around her Christmas song 'All I Want For Christmas'.

The 46-year-old singer has been ''surprised'' by how well the 1994 single - which she wrote and produced with Walter Afanasieff - has stood the test of time, and how it becomes more and more popular each year around the festive period.

Asked if she knew the hit would bring her so much success and revenue, she said: ''Oh my gosh, no no, never, no. I feel like this is something small compared to the rest of my catalogue. This song just continues to surprise me.''

Mariah - who has six-year-old twins Moroccan and Monroe with ex-husband Nick Cannon - loves it when she hears how the song has resonated with her fans.

She said: ''I'm very thankful that people seem to still have an attachment to it.

''It makes me feel good when people tell me that it's part of their lives.''

On Tuesday (14.11.17), Mariah released animated movie 'Mariah Carey's All I Want For Christmas Is You', next month she is bringing her 'All I Want For Christmas Is You' tour to the UK for the first time, and she's even selling festive treats inspired by the song.

Speaking about bringing the holiday tour across the Atlantic, she told Billboard magazine:

''It's the first time we're taking the show from the Beacon Theater. It's an intimate evening.''

In 2015, the 'We Belong Together' hitmaker turned the same song into a children's book for her twins.

At the time, she said: ''When I wrote 'All I Want For Christmas Is You'

it was my dream for it to become a classic Christmas song.

''I am so proud of the song's impact as it continues to create memories for fans each year. I am thrilled to be able to bring the story of the song to new generations of families with the picture book.''