Katy Perry is "open" to collaborating with former rival Taylor Swift.

Zedd and Katy Perry at 2019 iHeartRadio Music Awards

Zedd and Katy Perry at 2019 iHeartRadio Music Awards

The 'Teenage Dream' singer and the 29-year-old pop star had been at loggerheads since 2014, when it was claimed Katy had stolen some backing dancers from Taylor's 'Red Tour'.

After four years of fighting, Katy called for an end to their feud last May, when she sent a literal olive branch - which is a symbol of peace - to Taylor ahead of the start of her 'Reputation Stadium World Tour'.

When the 'Chained to the Rhythm' hitmaker walked the red carpet the iHeartRadio Music Awards at the Microsoft Theater in Los Angeles on Thursday evening (14.03.19), she admitted that she would be willing to work with Taylor.

When asked by 'Entertainment Tonight' if she'd like to make music with the 'Blank Space' star, she quipped: "I mean, I'm making music with Zedd, [so] I'm open."

Katy was joined on the carpet by her '365' collaborator Zedd, and the DJ joked that the former enemies could make music in AI form, after the pair were turned into robots for the music video for the song.

He laughed: "I programmed her to make music with anybody, it's great."

The 'Part of Me' hitmaker jokingly replied: "I'm a loveable AI."

The 'Roar' singer wanted to "set a good example for women" when she sent her heartfelt apology to the 'End Game' hitmaker.

According to sources, Katy's decision to end their feud came as she wanted to show "support" for the 'Look What You Made Me Do' hitmaker, and bring an end to women being pitted against each other in the entertainment industry.

An insider said at the time: "Katy planned a very personal, sweet apology and took time to write a kind note in hopes Taylor would see how much she cared about putting this behind them. Katy told friends if Taylor didn't accept this apology, she would keep trying because she is done holding on to the past and wants to be part of the change in today's society. She wants to set a good example for women, so she planned to never give up, if that is what it took.

"Katy hopes they finally can be supportive of each other's music and maybe one day soon even hang out together again. Katy realises they need to take it one day at a time, but that this is a great start."

The 34-year-old star reportedly hated being at loggerheads with Taylor, and often told close pals she wanted to put the past behind them.

The source added: "She hates that feeling of having bad blood. She often told friends she wanted to end this fight with Taylor, but didn't know how to make that happen."

Katy sent Taylor an olive branch along with a handwritten note, which the latter posted a video of on her Instagram story.

In the video, the 'Blank Space' hitmaker could be heard saying: "So I just got to my dressing room and found this actual olive branch. This means so much to me."