Reality TV star Kim Kardashian has filed for divorce from rapper Kanye West after almost seven years of marriage, according to a report.

The mega-celebrity couple's divorce proceedings come just weeks after US media reported the pair were living separately and going through counseling dealing with "regular relationship issues."

Kardashian is asking for joint custody of the couple's four children, it added, with her lawyer Laura Wasser reportedly handing in the divorce papers Friday.

Kardashian's publicist confirmed the divorce filing but did not provide further details.

The pair, who began dating in 2012 and married in a lavish ceremony in Italy two years later, rapidly became one of the world's most instantly recognizable couples.

But their union has been dogged for months by reports in the gossip press that their marriage was on the rocks as West has battled with mental health issues and launched an improbable and controversial foray into US politics.

The couple have four children: seven-year-old daughter North, son Saint, five, daughter Chicago, three, and 21-month-old son Psalm.

It would be the first divorce for West and the third for Kardashian, who came to fame with the US reality TV series "Keeping Up with the Kardashians" which followed the lives of her family members in Los Angeles.