The singer admitted that the pair have been working on a collaboration for "years", but insisted that it will happen soon.
She told Access Hollywood: "We are still trying to make a song together, Katy Perry and I.
"She is one of my favourite musicians as well as one of my favourite people in the industry. She's very uncalculated, very sure of herself, and that's something that's very rare in this industry to find. We connected really quickly."
Asked when the track will be released, she said: "The song will probably come out in a while. I can't say it's happening right now, but it's going to happen."
Rihanna recently defended her decision to duet with Chris Brown on the song 'Birthday Cake', saying: "There shouldn't be a divide, you know? It's music, and it's innocent."
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Watch Rihanna discuss working with Katy Perry below: