Billionaire businessman Warren Buffett said on Wednesday that congressional Republicans will not achieve tax reform, but rather a tax cut.

"I've never heard anyone describe a tax move as tax reform if their own taxes were getting increased. So I don't think we're talking about tax reform. Reform for one person is something else for the other," Buffett told Fox Business Network's Liz Claman.

"But it looks like we're moving more and more towards an overall tax cut. And that isn't where we started. We talked about being revenue neutral originally, but I think that the politics have evolved in such a way that if you're going to get anything done reasonably fast, it can't be a 1986-type massive reform act. So I think if we see a tax change, it isn't necessarily tax reform; it will be a tax cut. It will be called tax reform, though," the billionaire continued.

Buffett, who supported Democratic nominee Hillary Clinton in the 2016 presidential campaign, said he believes a tax bill will be passed by the end of this year.

"I think there's a pretty good chance. I probably think there's more of a chance of that than most people think. I think the Republicans need one, and if you don't make it too complicated, try and really change the code in a massive way, I think you probably can get it done," he said.

Buffett's comments come as President Trump and Republican lawmakers set their sights on passing tax legislation.

The president launched his new tax code pitch during a rally in Missouri on Wednesday, in which he took aim at Sen. Claire McCaskill (D-Mo.), saying voters should boot her out of office if she does not support his proposal.

"We must lower our taxes, and your senator, Claire McCaskill, she must do this for you, and if she doesn't, you have to vote her out of office," the president said.

Republicans are set to continue their work on tax legislation when they return from August recess next week.