R&B superstar Usher has called off his wedding to his pregnant fiancee.

The star was set to marry girlfriend Tameka Foster, but the nuptials were cancelled just hours before the couple were set to walk down the aisle.

The move came after reports that Usher's family - especially his mother who was recently sacked as his manager - strongly disapprove of his older girlfriend.

His people confirmed the surprise news but refused to say why the wedding was cancelled.

It's not known whether the couple will reschedule the ceremony or even if they are still an item.

The couple, who announced their engagement earlier in the year, are expecting a baby together in autumn, which will be Usher's first child, while it's the fourth for stylist Foster.

The R&B singer, real name Usher Raymond, is also expected to release his fifth album this year.

His 2005 album, Confessions, sold eight million copies in the US.