'Stop smoking weed you little b**tard', Mark Wahlberg tells Justin Bieber

Mark Wahlberg has branded Justin Bieber a "little b**tard" and has warned the teen icon to "stop smoking weed" or risk losing his glittery career.

During a live web chat with the Sun, the '2 Guns' star, who has had his share of run-ins with the law as a 16-year-old and served 45 days in prison after pleading guilty to an assault charge, urged the singer to change his naughty ways and pull up his socks.

The actor also implored the 'Baby' hit maker to work harder and make his mother, Pattie Mallette, proud.

Wahlberg asserted that Bieber's a nice enough kid, but his career can be short-lived if he doesn't stop getting into trouble.