Justin Bieber has apologised to Ronda Rousey for snubbing her little sister.

Justin Bieber

Justin Bieber

The 21-year-old pop star was recently accused by the MMA fighter of refusing to have his photograph taken with her 17-year-old sister Julie at the Cannes Film Festival, and although Justin claims he can't remember the incident, he has offered his apologies.

He said: "I guess, supposedly, she asked for a picture with her sister or something, and I guess I said no?

"But I don't remember this happening so, Ronda, I'm sorry. Don't kick my ass!"

The 'Boyfriend' hitmaker subsequently revealed he's keen to improve his own fighting skills, and made particular reference to Ronda's recent knockout loss to Holly Holm in Australia.

He told 'Entertainment Tonight': "I would like to get better at boxing . . . Did you see Ronda Rousey?

"She got knocked out cold! Oh my God, she got knocked out so bad. Yeah no, she got pummeled."

Justin also revealed he'd like to "have a family, a wife, some kids . . . an indoor basketball court and an indoor pool".

He added: "I want to build it and stuff, and find the right place."