Socialite Paris Hilton has apologised to American stylist Kim Kardashian after insulting her on a radio show.

Intouchweekly.hollywood.com reports while speaking on a radio show, Hilton had said, "I would not want (Kim's butt) - it's gross. It reminds me of cottage cheese inside a big trash bag."

Hilton said this on a Las Vegas radio-show April 14. However, when a part of the show was posted online, Hilton was remorseful and realised she was wrong.

She now says: "I felt really bad afterward, so I contacted Kim and apologised. It was a silly thing to say. I was just joking around and I made a stupid joke. Kim's hot!'

Kim acknowledged the apology and responded: "Paris and I have been friends since we were kids and I'm glad she made the effort to say she's sorry."