Rihanna won't tell fans when her new album is coming out.

The 26-year-old singer is very proud of her new record, which is rumoured to be called 'Lost Files', but won't announce a release date, though she hinted it will be previewed one track at a time.

She said: ''I can't give you any hints of when it will drop. It's going to be great, that's all I'm going to tell you and I'm excited about it.

''I can't wait for everybody to hear [the music] little by little. ... little by little. I can't wait.''

And the 'Diamonds' hitmaker admitted she is constantly trying to ''outdo'' what she has recorded before.

Speaking at a meet-and-greet with fans in Virginia, she said: ''I try to battle myself and outdo everything I've done and that's been the hardest thing to do. You start overthinking things at times.''

While Rihanna is keeping tight-lipped about the record, her 'We Found Love' collaborator Calvin Harris recently admitted some material he sent to her hasn't made it onto the finished album.

He said: ''No I'm not on the Rihanna album.

''I did a few things for it but they don't get back to you. There are a lot of people involved!

''She listens to everything - I know that - but she's got a strong idea and identity and an idea of what her album should sound like.''

However, the 30-year-old DJ - who, along with Rihanna, is signed to Jay Z's Roc Nation record label - insists he's not bothered about being snubbed from her latest LP.

He said: ''It's not like they put me on 'We Found Love' because I'm signed to Roc, they did it because it's a f**king good song.

''But it's OK because I'm working on my stuff and it's going fine so I'm not concerned about it.''