Demi Lovato believes in aliens.

She told Elle Canada: "Aliens! I've seen a UFO. A couple of years ago, I was walking outside and I looked up and it was almost like there was a worm in the sky. It was changing shapes and moving all over the place."

Demi's close friend Nick Jonas, 23, previously revealed that he also shares her belief and they often chat about aliens.

He said: "She and I have talked about this a lot. I am on board. So when I was 14 maybe, I was in my backyard playing basketball with some friends, and I looked up in the sky and there were three flying saucers.

"This is Hollywood, so everyone was like, 'It's a movie, it's a movie set,' and I was convinced it was real. I looked up online and there were three identical sightings in other states. So I am a firm believer in aliens and extraterrestrial life."

Meanwhile, Demi believes her honesty is key to maintaining her strong relationship with fans.

She said: "Honesty gives me a way to relate to my fans. If I'm not honest, then I can't open up to them and they can't relate to me at all. I try to inspire people by saying 'If I can go through that, you can go through that.'"

And she is extremely passionate about her charity work but admitted it is frustrating when it gets overlooked.

She said: "It's frustrating to see my charity work overshadowed by silly things, but you have to roll with the punches…It's the thing that keeps me strong, makes me feel that when I want to give up, I know I have this going for me."