Olivia Rodrigo has promised fans her new album is "so close to being done".

The 'good 4 u' hitmaker has marked the two-year milestone of her record-breaking debut album, 'SOUR', and teased that it won't be long before fans get to hear her new material.

Olivia wrote on Instagram: "oh man oh man oh man. SOUR turns 2 years old today. no words could ever describe how much this album means to me and how insanely grateful I feel for every blessing it has brought into my life. the new stuff is so so so so so close to being done I pinky promise. (sic)"

Earlier this year, Olivia teased that she has been hard at work on "so many new songs".

The Grammy winner took to her Instagram Stories to share a clip of her and producer Dan Nigro head-banging along to a piano piece in the studio.

She captioned the clip: “Working on so many new songs I’m excited to show u.

“Thank u for everything.”

The 20-year-old singer had previously teased that she's "so excited" for all the new music "that 2023 will bring".

Speaking to her supporters in a recorded message that was sent to her top listeners on Spotify, to coincide with 2022's Spotify Wrapped, she said: "I just wanted to say thank you so much for listening to my music this year.

"I really, truly couldn’t be more grateful and I am so excited for next year, and all of the new things and new music that 2023 will bring."

Olivia became the first female artist to have three solo songs on a single album reach a billion streams on the streaming platform.

She made history after her third hit record from 'SOUR', 'deja vu', exceeded the one-billion mark and 'drivers license' and 'good 4 u' also crossed the milestone.

Producer Dan also shared a studio snap of the pair on his Instagram Story in August, confirming a previous report that they are hard at work on the follow-up.

After the whirlwind success of her record-breaking debut LP, the singer reunited with the studio wizard behind all but one of the 11 tracks on the chart-topping 2021 record