Sen. Bernie Sanders (I., Vt.) said in an interview airing Sunday he will support whichever candidate has the best chance of defeating President Donald Trump in 2020, even if it's not himself.

MSNBC's Al Sharpton interviewed Sanders at the National Action Network conference and asked Sanders—one of numerous rumored 2020 Democratic contenders—if he'd decided to run for president again.

"I have not made that decision," Sanders said.

"What will make you make the decision?" Sharpton asked.

"I want more than anything to see that Trump is defeated, and what I will assess at the proper time is who is the best candidate, and I mean that sincerely," Sanders said. "Everybody has an ego. I have an ego. But what is most important for this country is that we come together, to transform America … and to defeat Donald Trump.

"And at the appropriate time, right now my focus is on 2018, doing everything I can to see the Democrats regain control of the House, maybe even the Senate … But at the appropriate time, we're going to look around us and say, ‘Which candidate is the best candidate to defeat Trump?'

"And you'll go with that?" Sharpton asked.

"Yes," Sanders said.

Sanders said he believed Democrats "will be supportive" of him if they feel he's the best candidate to defeat Trump.

Sanders mounted a surprisingly sturdy bid for the Democratic nomination in 2016 against frontrunner Hillary Clinton, winning 22 caucuses and primaries.