The 44-year-old producer spilled the news in a television interview while he was revealing his reasons for not returning as a mentor on 'The Voice'.
Appearing on 'TODAY', he revealed: ''Honestly, I have to work. I have so much work to do. It was so much fun and while I was doing it, helping other people was like a drug for me. I couldn't get enough of helping them but I have work to do, music to make, there's so many records. Ariana Grande's album's amazing, the Justin Timberlake album's amazing.''
The 'Happy' hitmaker also hinted that his group N.E.R.D's long-awaited new record, which was confirmed back in 2015, is still in the works.
He continued: ''There's another album that I can't talk about but my fans know all about it. I can't [say what] I gotta be a good boy and it's exciting - it's so much work that I got done being off [the show] but I'm so grateful and I had such a great time [on there].''
Earlier this year, Pharrell stated that the comeback - the group's first album since 2010's 'Nothing' - was ''feeling really good, really special.''
As for Ariana, her last record was 2016's 'Dangerous Woman' and Justin Timberlake hasn't released a full-length studio album since 2013's 'The 20/20 Experience' and 'The 20/20 Experience - 2 of 2'.
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