Sen. Elizabeth Warren, D-Mass., said she'd be "happy" to meet with Microsoft founder Bill Gates to discuss her policy plan after the billionaire joked that her wealth tax might cost him $100 billion.

"I'm always happy to meet with people, even if we have different views," the 2020 presidential candidate tweeted Wednesday evening. "@BillGates, if we get the chance, I'd love to explain exactly how much you'd pay under my wealth tax. (I promise it's not $100 billion.)"

Warren has proposed a 6 percent wealth tax on assets above $1 billion to help fund "Medicare for All." The wealth tax proposal has come under criticism from billionaires like financier Leon Cooperman and JP Morgan Chase's Jamie Dimon.

“Yes, billionaires will have to pay a little more, but they will still likely pay less than what they would earn just from putting their assets into an index fund and doing nothing,” Warren wrote in her plan released Friday. Warren has also proposed a series of other taxes aimed at the wealthiest Americans.

Speaking at The New York Times' DealBook conference on Wednesday, Gates said he's "paid over $10 billion in taxes."

"I’ve paid more than anyone in taxes," he continued. "If I had to pay $20 billion, it’s fine. But when you say I should pay $100 billion, okay, then I’m starting to do a little math about what I have left over. I’m just kidding."

Gates added that he was unsure whether Warren would meet with a billionaire to discuss policy.

"I’m not sure how open-minded she is — or that she’d even be willing to sit down with somebody who has large amounts of money,” Gates said.

Gates declined to say who he would vote for in a hypothetical matchup between Warren and President Donald Trump.

"I’m not going to make political declarations," Gates said. "But I do think no matter what policy somebody has in mind, a professional approach is even, as much as I disagree with some of the policy things that are out there, I do think a professional approach to the office is… whoever I decide will have the more professional approach in the current situation probably is the thing that I will weigh the most. And I hope that the more professional candidate is an electable candidate."

Gates is worth an estimated $109 billion, according to Bloomberg.