R&B star Usher has no regrets about his failed marriage to Tameka Foster, calling the relationship his "best mistake".

The Yeah hitmaker endured a highly-publicised and lengthy court battle with Foster following the breakdown of their two-year marriage in 2009, but Usher remains positive about the experience.

In an interview for the September (14) issue of O Magazine, the singer describes walking down the aisle at the age of 28 his "best mistake", adding, "Most people probably think I regret it because I ended up getting divorced, but it helped me learn that sometimes I think I know more than I actually do."

Following their split, the former couple began a heated custody battle and in 2012, Usher was awarded primary custody of their two sons, Usher Raymond V, six, and Naviyd Ely, five.