Miley Cyrus has denied being unfaithful to Liam Hemsworth just days after the actor filed for divorce.

The couple, who tied the knot in December last year after a decade of off-and-on dating, announced their separation earlier this month.

In a series of tweets, 26-year-old Cyrus has insisted she has "nothing to hide" and admits her marriage didn't end because she cheated on the Australian actor.

She said: "I can accept that the life I've chosen means I must live completely open and transparent with my fans who I love, and the public, 100% of the time.

"What I cannot accept is being told I'm lying to cover up a crime I haven't committed. I have nothing to hide."

Cyrus added: "I can admit to a lot of things but I refuse to admit that my marriage ended because of cheating. Liam and I have been together for a decade. I've said it before & it remains true, I love Liam and always will."

Hemsworth filed a petition to end his marriage to the American pop star and actress in Los Angeles on Wednesday (August 21).

The request states that he is asking for a dissolution of their marriage, and that they do not have children.

According to US website TMZ, he cited "irreconcilable differences" as the reason for their split in the court documents.

The couple, who first met while filming 2010's The Last Song and dated on and off for years before tying the knot in December 2018, announced on August 10 that they were going their separate ways so they can "focus on themselves and careers.