After her tell-it-all interview with James Corden on "Carpool Karaoke" last month, Katy Perry has once again opened up about her ongoing dispute with Taylor Swift, who apparently wrote, "Bad Blood" for her friend-turned-enemy. The "Roar" singer insisted it was Tay who started the feud after the former hired some of the latter's backup dancers for her concert tour.

'It's time for her to finish it.'

The "Dark Horse" artist added Taylor Swift should finish what she started. Katy Perry also revealed she tried to patch things up by reaching out to her co-singer who allegedly refused to talk to her.

The 32-year-old Guinness awardee even warned Tay for the effects of her acts.

"It's all about karma," she told James Corden. "I think personally that women together, not divided, with none of this petty sh*t, women together will heal the world."

For her interview with NME, Katy Perry admitted no one asked her about her ongoing feud with the "Shake It Off" artist until James Corden brought up the issue during her "Carpool Karaoke" episode. The "Teenage Dream" singer is just hoping that she could turn a blind eye to controversies like this.

"But I'm also not a pushover, you know? Especially when someone tries to assassinate my character with little girls [Swifties]," Katy Perry said, referring to Taylor Swift's fans.

'Now we got bad blood.'

The "Thinking Of You" singer has emphasized that her disagreement with Tay has nothing to do with men. Katy Perry previously dated John Mayer after his brief romance with Taylor Swift. The bad blood between the two began when the Brit awardee hired some of Tay's backup dancers for her world tour.

Lockhart Brownlie said Katy Perry's people have reached out to him to join the singer's "Prism" concert series in the midst of Taylor Swift's promotion of "Red" album.

Then here comes "Bad Blood" which was co-written by Max Martin, a close friend of the "Wide Awake" singer.

The Swedish songwriter stated he is unaware of the story behind "Bad Blood." Katy Perry, on the other hand, said she does not what to involve Max Martin in her feud with the co-artist. The singer added she wants to be fair with her longtime colleague by letting him do his craft regardless of the artist he is working with.

Meanwhile, Taylor Swift previously said that she was unsure whether her co-singer has treated her like a friend before they stopped communicating. After giving her side of the story, the "Speak Now" artist promised not to talk about her issue with Katy Perry again.