The pair have been writing songs in Palm Springs and Charli has called it the "best music ever".
She wrote on Instagram: "@tovelo and i have been out in Palm Springs writing songs together for a week (tested and safe) and we been making the best music ever!!!!! excited for u guys to hear things, but in the meantime, checkout my updated motherf****** future playlist at the link in my bio and make sure u play it start to finish SUPER LOUD!!!! (sic)."
Tove Lo shared the message on her page and wrote: "Yes. Love writing with you."
Meanwhile, Charli, 28, recently admitted she feels like an "outsider" in the music industry.
She tweeted: "i feel like outside of my fans I don’t really provide people with the opportunity to feel much ownership over me or my decisions, which is maybe why i have a sort of outsider status within pop music and also experience rejection from the “industry” side of music sometimes (sic)".
And she added: "i always give my collaborators credit. my producers/mixers/artists I collaborate with etc. i have never once pretended I am solely responsible for the songs I release - but I also recognize that none of my art would be the same or even possible without my own vision & talent (sic)."
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