Biden: 'I've decided I’m not going to decide not to run' in 2020

— -- Former Vice President Joe Biden isn't ruling out running for president in 2020.

"I haven’t decided to run," he said in an interview with Vanity Fair, "but I’ve decided I’m not going to decide not to run. We’ll see what happens."

Biden previously ran unsuccessfully in 1988 and 2008, and was actively considering a 2016 run but decided against it after his son Beau Biden died from brain cancer in 2015.

In the interview with Vanity Fair, which was timed to be released with his new book "Promise Me, Dad," Biden said when Beau got sick there was "no question" in his mind that he was going to run in 2016.

"I had planned on running, and I wasn’t running against Hillary or Bernie or anybody else. Honest to God, I thought that I was the best suited for the moment to be president," Biden said.

As for the actual 2016 candidates, Hillary Clinton has already repeatedly ruled out another presidential run and President Donald Trump has already established a re-election team.

Biden, who campaigned for Clinton in 2015 and gave speeches including scathing rebukes of Trump, did not mince words when talking about him now, calling Trump "self-referential and uninformed," and Biden portrayed Trump as a threat to the country's principles.

"This sounds corny,” Biden said in the Vanity Fair interview, "but everything the founders did was to erect institutions that made it more difficult to abuse power. That’s why they have three different branches of government. And what really worries me about this administration is the frontal attack on those institutions that, if they were lost, makes the abuse of power so much more available."