Katy Perry appears to have ticked off Niall Horan by joking about his alleged efforts to flirt with her.

The Roar hitmaker recently told the hosts of Australian morning radio show Fitzy & Wippa that she thought the This Town singer had a crush on her.

She said, "I see him (Niall) around all the time. He's always trying to like, get my number, to like, maybe flirt with me but I'm like, 'I could babysit you. I'm like your mom!'"

The One Direction star has picked up on Katy's comments - and he's not amused.

Appearing on Australia's The Project TV show on Thursday (29Jun17), the singer said, "Katy, please stop being mean to me. She's just finding any excuse now to just patronize me and go around spreading rumors about me. I just want to be your friend!"

As for their nine-year age difference, Horan noted, "She is talking like she is about 55 years older than me. She is not that much older than me."

Meanwhile, Katy is also taking credit for Niall's pop career, revealing she "helped him get through" The X Factor auditions in 2010, before he became a member of the boy band.

"Niall's amazing, I love him, and I think we feel very connected in a way because I, like, helped him get through The X Factor to join his group," she said on Wednesday (28Jun17). "He's become a big star and I'm like, 'Cool, I guess that means I have taste?'"

Perry is now taking her taste talents to the American Idol reboot, which will hit TV in America later this year.