Kanye West feels ''purely happy'' to be married to Kim Kardashian West.

The 40-year-old rapper and the 'Keeping Up with the Kardashians' star - who have four-year-old daughter North, two-year-old son Saint, and four-month-old daughter Chicago together - celebrated their fourth wedding anniversary on Thursday (24.05.18), and Kanye took to social media to gush over his partner.

In one tweet, he wrote: ''gratitude and happiness best describe what my wife means to me. I'm deeply grateful and purely happy (sic)''

He also shared a video clip of his 37-year-old spouse dancing to Selena song 'Bidi Bidi Bom Bom', which was filmed during Halloween last year when Kim dressed up as the late singer.

The clip was captioned with several fire emojis, and Kanye wrote: ''This is one of my favorite moments.''

Meanwhile, Kim also shared a loving tribute to her husband on social media, when she took to both Twitter and Instagram to share a picture from their wedding day.

She wrote in the sweet caption: ''4 years down and forever to go.... Thank you babe for giving me our family and caring so much about us. Thank you for inspiring me on a daily, I'm so lucky. I can't wait for forever... Happy Anniversary (sic)''

The couple's four-year anniversary comes as Kim revealed recently that she would be open to the idea of having a fourth child with the 'Heartless' rapper.

Kim and Kanye used a surrogate mother for their youngest daughter Chicago after Kim was advised against getting pregnant again, and the beauty ''enjoyed'' the surrogacy process so much she's considering using one again to have a fourth child.

She said: ''I would have maybe one more [child]. I really, really enjoyed the surrogacy process. I will say, when it came to the breastfeeding time, I was like, 'Okay, this is the best decision I ever made.'

''It's a game changer, having to not go through [nursing] every few hours. I can spend so much more time with the older kids and getting them used to the baby.''