Beyoncé Knowles has congratulated Kim Kardashian and Kanye West on the birth of their baby girl.

Reality TV star Kardashian gave birth to the couple's first child five weeks premature over the weekend.

Beyoncé took to her official website to send her best wishes to the new parents, with a message and photo of the pair together.

The international superstar wrote: "Congratulations Kim & Kanye, enjoy this beautiful moment together – Beyoncé." 

Kardashian and West are yet to officially announce their happy news, although family and friends have sent a host of well wishes.

Kardashian's younger sister Khloe took to Twitter to gush about the news: “I cannot even begin 2describe the miracle that is now apart of our family. Mommy/baby are healthy &resting. We appreciate all of the love.”

She added: “More info will come when the time is right! Thank you all for understanding! We love you all dearly! Overwhelmed with love right now (sic)."

Kardashian's close friend Jonathan Cheban revealed Kim is doing well after the birth.

He told People: "Kim is doing amazing and couldn't be happier, I'm so thrilled for her and Kanye. Kim was glowing."

Kardashian and West began dating in April last year after years of friendship.

West announced the couple were expecting a new family addition live on stage in December 2012. 

The pair's daughter will join sister Kourtney and Scott Disick's two children - Mason, three, and 11-month-old Penelope.