Country singer Billy and his wife have announced their separation and filed divorce papers this week citing "irreconcilable differences", reported Contactmusic.

"As you can imagine, this is a very difficult time for our family. We are trying to work through some personal matters. We appreciate your thoughts and prayers," they said in a statement.

Friends said it was inevitable the couple - who have three children, 17-year-old Miley, Braison, 16, and Noah, 10, - would split but insisted nobody else is involved.

"It was a long time coming. It is the best thing for both of them," said a source close to the couple.

The couple married in December 1992 and Billy adopted Tish's two children, Brandi and Trace, from her previous marriage, in addition to the three children he had with her.He also has a son, Christopher, from his relationship with Kristen Luckey.

The family initially lived on a 500-acre farm near Nashville, Tennessee, before moving to Los Angeles following the success of Miley's TV show 'Hannah Montana', in which Billy also appears.