Jason Derulo is feeling optimistic about TikTok's fate ... despite the ticking countdown to the social media app's ban in the United States.

The singer shared his take on the looming ban on Kannon with a K's "Open House Party" radio show, where he defended TikTok as far "too valuable" to just go dark.

As he sees it ... there is just too much at stake for the social media app to shut down, noting there are a lot of people behind the scenes who want to find a way to keep TikTok available in the U.S.

Jason, who has 66 million followers on the app, says he would love to buy TikTok ... if only the company would take his follower count for ownership clout.

In reality, JD is convinced one of the many billionaires who've expressed interest in saving TikTok will likely be the key to the platform's stateside rescue.

Though, Jason may be feeling a bit more nervous now ... given the Supreme Court upheld the TikTok ban Friday, making way for its potential ban on American app stores starting Sunday.

So, it's a good thing Jason has a contingency plan in place in case the shutdown happens.

As he tells Kannon ... he's open to using other social media alternatives, including TikTok competitor RedNote. However, he thinks whoever does live-streaming best will eventually come out on top.

We can't just let Jason's sick dance moves -- which you can get a taste of in the TMZ vid above -- go to waste!!!

Catch more of Jason's opinions when the full interview, which was recorded Thursday, airs in its entirety on Kannon's syndicated radio show.