Showrunner and EP Lorne Michaels made the announcement Wednesday ... also sharing that Alec will return as President Trump, and so would Maya Rudolph, who played a hilarious version of Kamala Harris last time around.

But, on Biden -- who's been portrayed by Woody Harrelson and Jason Sudeikis of late -- Lorne told Vulture they were probably gonna give Jim a shot ... with conditions, it seems.

He says, "There was some interest on his part. And, then we responded, obviously, positively." He adds there were caveats, explaining ... "But, it came down to discussions about what the take was. He and Colin Jost had a bunch of talks. He and I as well. He will give the part energy and strength, and … [Laughs.] Hopefully it’s funny."

Oh, it's gotta be.

It's interesting that Lorne wanted to feel out how Jim would go about portraying the former Veep. The last time 'SNL' spoofed him ... they often made Biden out to be rambling, kooky and kinda creepy with his touchy-feely-ness.

Ya gotta wonder what the take will be now ... with the new backdrops of the coronavirus pandemic and Biden being the Democratic nominee.