Former Vice President Al Gore endorsed Vice President Kamala Harris on Sunday.

"As a prosecutor, [Kamala Harris] took on Big Oil companies -- and won. As [VP], she cast the tie-breaking vote to pass the most significant investment in climate solutions in history, the Inflation Reduction Act. That's the kind of climate champion we need in the White House," he wrote on X.

"With so much at stake in this year's election -- from strengthening democracy in the US and abroad, to expanding opportunity for the American people, to accelerating climate action -- I’m proud to endorse Kamala Harris for President," he added.

-ABC News' Oren Oppenheim

During a quick stop at a diner in Minnesota on Sunday morning, Sen. JD Vance on Sunday spoke about his past criticisms of former President Donald Trump.

When asked by ABC News if he and Trump have talked about his past criticism of the former president, Vance said yes, adding that Trump "doesn't care about what I said eight years ago."

"I mean, look, President Trump and I have talked a lot about this," Vance said. "In fact, I sometimes joke that I wish that he had the memory of Joe Biden, because he's got a memory like a steel trap, and he certainly remembers criticisms that people have made."

"But this is where the media, I think, really misses Trump -- Donald Trump accepts that people can change their mind, and you ask, 'Why did I change my mind on Donald Trump?' Because his agenda made people's lives better," Vance said.

"This whole thing is not about red team versus blue team or winning an election for its own sake. It's about getting a chance to govern so that you can bring down the cost of groceries, close that border and stop the fentanyl coming across our country for four years,” Vance continued, saying he was "wrong" about Trump.

"He did a better job of that than anybody that I've ever seen as president in my lifetime. So I changed my mind, because he did a good job. And that's what you do when people do a good job and you're wrong. I've talked to President Trump a lot about it, but look, he, I mean, he just, he doesn't... He doesn't care about what I said eight years ago. He cares about whether we together [and] can govern the country successful.”

When asked again if the two have talked about the subject, specifically in the last week since his comments have resurfaced, Vance admitted that they haven't spoken about it and their conversations have focused on the race ahead.

-ABC News' Kelsey Walsh, Soorin Kim and Hannah Demissie