The iconic 86-year-old filmmaker insisted he didn't have the "choice" or control to make studios wait for follow-ups to his 1979 and 1982 sci-fi classics, and he "wasn't happy" when the companies decided to make follow-ups without getting him on board.
He told Vanity Fair magazine: "I'm the author of two franchises. Most directors in Hollywood — certainly, let's say, at my level — don't let that stuff go".
"But I did 'Alien' as my second movie, so I didn't have much choice. And 'Blade Runner' was my third movie. So, I had no choice because I had very tough partners".
"It was kind of 'Welcome to Hollywood.' I was never told or asked [about sequels]. You can imagine I wasn't happy".
'Blade Runner 2049' was released in 2017, while the 'Alien' franchise expanded with 'Aliens' in 1986, 'Alien3' in 1992 and 1997's 'Alien Resurrection', before Scott returned to the franchise to helm 2012's 'Prometheus' and then 'Alien: Covenant' four year slater.
He pondered: "I was slow out the starting gate. I mean, I should have done the sequels to 'Alien' and to 'Blade Runner'. You change over the years".
"At that time, I didn't want to go through it again. So Jim Cameron came in — and then David Fincher — on 'Alien'".
Scott did actually hope to direct the 'Blade Runner' sequel, but the chance to revisit 'Alien' came up and Denis Villeneuve instead ended up at the helm.
He added: "I was regretful, although he did a good job".
The filmmaker will return to the dystopian franchise with upcoming Amazon Studios series 'Blade Runner 2099'.
He previously told Empire magazine: "I'm one of the producers. It's all set years on. To me, it circles the idea of Aldous Huxley's Brave New World".
Scott has been looking to return to the franchise for a long time now, and back in 2018 he teased the possibility of "another story" to delve into.
He told Digital Spy at the time: "I think there is another story. I've got another one ready to evolve and be developed, so there is certainly one to be done for sure".