Kim Kardashian West is worried her daughter's dislike for her brother isn't a ''phase''.

The 'Keeping Up With The Kardashians' star has admitted she is concerned about how ''jealous'' her four-year-old daughter North gets about her 20-month-old brother Saint.

Speaking as she guest hosted 'Live! With Kelly and Ryan', she said: ''I don't know if it's 'cause she's the older sister ... I don't know what it is; I thought it was a phase. She does not like her brother. It's so hard for me.

''I thought it was like, 'OK, a couple months; she's just warming up to it.' She got so jealous when I would breastfeed and all that stuff. Now, the phase isn't going away!''

Meanwhile, Kim previously admitted she is ''terrified'' of raising her children around social media.

She said: ''I'm terrified. I think that social media is one of the most important tools if you're building a brand ... and just to share your life, I think it's really fun. But I didn't grow up in a world of social media.

''My kids are a little too young to want it now, but I think it's so important. It's about boundaries. At home, I don't have my phone. Dinner time, breakfast time, there's no phone.''

The 36-year-old television personality also recently revealed she writes a letter to her children each year to give to them when they're 21-years-old.

She revealed on Twitter: ''I found a 3 page letter my dad wrote me right after high school about life and it's so special to have. I re-read it last night. I write my kids a letter each year reflecting on the year we had together & fun memories. I'll give the letters to them when they turn 21.''