Vice President Joe Biden. AP Photo/Andrew Harnik Vice President Joe Biden — who is reportedly on the verge of making an announcement about a potential bid for the presidency — may have taken veiled shots at potential rivals Hillary Clinton and Sen. Bernie Sanders (I-Vermont) in a speech Monday.

At the first Democratic presidential debate last week, Clinton, the former secretary of state, declared that she was proud of making an enemy of Republicans.

Speaking about at the White House Summit on Climate Change on Monday, Biden appeared to draw a contrast between himself and Clinton.

He said he didn't "consider Republicans enemies" when discussing cooperation between himself and Rep. Darrell Issa (R-California), the former chair of the House Oversight Committee.

"Darrell Issa, not a Republican friend of mine, he's a friend. I don't consider Republicans enemies, they're friends," Biden said, while discussing the implementation of the 2009 stimulus. "Even Darrell Issa said that this is how every government program should be administered."

And while speaking about renewable energy policies several minutes later, Biden also made a quick aside about his lack of animosity towards Wall Street. It implicitly drew a clear contrast between himself and Sanders, who has skyrocketed in polls amid his constant populist critique of the financial industry.

"By the way, I'm not one of the guys, you know, 'Let's go after the rich and the powerful and they're the problem.' They're not a problem, but everybody has to do their part, man," Biden said.

Biden has made several unprompted references to Sanders in recent weeks.

During the keynote address at the Concordia Summit in Manhattan earlier this month, Biden told an audience that he was a realist, not a populist like Sanders.

"I'm no Bernie Sanders," Biden said. "He's a great guy by the way. He really is. I'm not a populist. But I'm a realist."

And at a parade in September, Biden told a union crowd that the senator was "doing a hell of a job, by the way."

Various reports emerged Monday that said Biden could announce a presidential bid sometime in the next several days. Though he made no reference to his deliberations, he highlighted his accomplishments on issues from climate change to gun control.

Biden, who is known for speaking off-the-cuff, mentioned Monday that he had watched last week's Democratic debate.