Kim Kardashian West's son Saint is her ''twin''.

The 36-year-old American television personality believes her and 16-month-old child have the same personality and she claims the pair of them are both ''so sweet'', whereas her three-year-old daughter North has the same qualities as the 'Selfish' author's husband Kanye West.

Speaking about her brood on 'The Ellen DeGeneres Show', which will air on Thursday (27.04.17), the raven-haired beauty said: ''He's my twin. He's literally my twin personality. He's so sweet. And he's just such a good good boy. Just such a good person.

''[North] She's really really smart, actually. She knows how to outsmart us -- if she thinks she does. But she is Kanye's twin. Same personality, says the same wild things. Those two.''

And the 'Keeping Up With the Kardashians' star has revealed her oldest child will often bully her brother because she is ''so jealous'' of him, especially when he would nestle into the reality star's chest to be breastfed.

Kim explained: ''North just beats him [Saint] up all day long ... she's just awful. She is so jealous, and I thought it was a phase -- it's not going away. She just says boys aren't allowed in her room. Like, when she's gone at school, I'm like, 'It's time let's go in her room! Do whatever you want - go crazy!'

''When I was breastfeeding him, [North] was so jealous I had to get a little milk box and put it in the other bra with a straw so she would drink and he would drink. She's so jealous. It's crazy. The things you do.''

And the fashion icon has praised her 39-year-old spouse for his ''romantic'' tendencies, and feels pressure to plan his 40th birthday bash when he hits the milestone on June 8.

She explained: ''He does the most amazing, romantic, over-the-top, crazy, wild things that you would never even imagine for me. So the pressure is so on.

''I think I still want it to be intimate, maybe small. Not too crazy. Not too overwhelming just yet.''