The 44th POTUS released a statement Sunday a few minutes ago ... and, it's a glowing tribute to the sitting president -- a man he calls a "patriot of the highest order."

Obama says he came to admire Biden's character in the years they worked alongside one another as president and vice president ... character he says has helped Biden save the country from ruin over the past few years.

Barack points out Joe's economic, international, and climate change victories during his administration ... though he admits his greatest accomplishment was keeping Trump out of office in 2020.

Obama says such an outstanding track record gave Biden every right to run for reelection, adding he's never known Joe to back down from a fight -- so, he knows dropping out of the race must've been tough on the sitting president.

Then Barack gets into the race as it currently stands ... and, his comments are interesting because he doesn't immediately come out and back Kamala Harris.

Instead, Barack says he has "extraordinary confidence that the leaders of our party will be able to create a process from which an outstanding nominee emerges" ... so, basically he's waiting to see how everyone's gonna fair in an open field.

Biden's already backed Kamala Harris -- who says she's honored by his endorsement -- but, it seems Barack's not weighing in until the party determines the next candidate. He pulled the same move back in 2016 too BTW, waiting until after Hillary Clinton won the nom to endorse her.

Worth noting ... reports recently came out saying Barack had told Democratic allies Joe needed to drop out for the good of the party -- though he wasn't saying this to his face.